1 /*
2 * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2024, 2025, Alibaba Group Holding Limited. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "gc/shared/barrierSet.hpp"
27 #include "gc/shared/c2/barrierSetC2.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/allocation.inline.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "opto/ad.hpp"
32 #include "opto/callGenerator.hpp"
33 #include "opto/castnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/connode.hpp"
36 #include "opto/loopnode.hpp"
37 #include "opto/machnode.hpp"
38 #include "opto/matcher.hpp"
39 #include "opto/node.hpp"
40 #include "opto/opcodes.hpp"
41 #include "opto/reachability.hpp"
42 #include "opto/regmask.hpp"
43 #include "opto/rootnode.hpp"
44 #include "opto/type.hpp"
45 #include "utilities/copy.hpp"
46 #include "utilities/macros.hpp"
47 #include "utilities/powerOfTwo.hpp"
48 #include "utilities/stringUtils.hpp"
49
50 class RegMask;
51 // #include "phase.hpp"
52 class PhaseTransform;
53 class PhaseGVN;
54
55 // Arena we are currently building Nodes in
56 const uint Node::NotAMachineReg = 0xffff0000;
57
58 #ifndef PRODUCT
59 extern uint nodes_created;
60 #endif
61 #ifdef __clang__
62 #pragma clang diagnostic push
63 #pragma GCC diagnostic ignored "-Wuninitialized"
64 #endif
65
66 #ifdef ASSERT
67
68 //-------------------------- construct_node------------------------------------
69 // Set a breakpoint here to identify where a particular node index is built.
70 void Node::verify_construction() {
71 _debug_orig = nullptr;
72 // The decimal digits of _debug_idx are <compile_id> followed by 10 digits of <_idx>
73 Compile* C = Compile::current();
74 assert(C->unique() < (INT_MAX - 1), "Node limit exceeded INT_MAX");
75 uint64_t new_debug_idx = (uint64_t)C->compile_id() * 10000000000 + _idx;
76 set_debug_idx(new_debug_idx);
77 if (!C->phase_optimize_finished()) {
78 // Only check assert during parsing and optimization phase. Skip it while generating code.
79 assert(C->live_nodes() <= C->max_node_limit(), "Live Node limit exceeded limit");
80 }
81 if (BreakAtNode != 0 && (_debug_idx == BreakAtNode || (uint64_t)_idx == BreakAtNode)) {
82 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT, _idx, _debug_idx);
83 BREAKPOINT;
84 }
85 #if OPTO_DU_ITERATOR_ASSERT
86 _last_del = nullptr;
87 _del_tick = 0;
88 #endif
89 _hash_lock = 0;
90 }
91
92
93 // #ifdef ASSERT ...
94
95 #if OPTO_DU_ITERATOR_ASSERT
96 void DUIterator_Common::sample(const Node* node) {
97 _vdui = VerifyDUIterators;
98 _node = node;
99 _outcnt = node->_outcnt;
100 _del_tick = node->_del_tick;
101 _last = nullptr;
102 }
103
104 void DUIterator_Common::verify(const Node* node, bool at_end_ok) {
105 assert(_node == node, "consistent iterator source");
106 assert(_del_tick == node->_del_tick, "no unexpected deletions allowed");
107 }
108
109 void DUIterator_Common::verify_resync() {
110 // Ensure that the loop body has just deleted the last guy produced.
111 const Node* node = _node;
112 // Ensure that at least one copy of the last-seen edge was deleted.
113 // Note: It is OK to delete multiple copies of the last-seen edge.
114 // Unfortunately, we have no way to verify that all the deletions delete
115 // that same edge. On this point we must use the Honor System.
116 assert(node->_del_tick >= _del_tick+1, "must have deleted an edge");
117 assert(node->_last_del == _last, "must have deleted the edge just produced");
118 // We liked this deletion, so accept the resulting outcnt and tick.
119 _outcnt = node->_outcnt;
120 _del_tick = node->_del_tick;
121 }
122
123 void DUIterator_Common::reset(const DUIterator_Common& that) {
124 if (this == &that) return; // ignore assignment to self
125 if (!_vdui) {
126 // We need to initialize everything, overwriting garbage values.
127 _last = that._last;
128 _vdui = that._vdui;
129 }
130 // Note: It is legal (though odd) for an iterator over some node x
131 // to be reassigned to iterate over another node y. Some doubly-nested
132 // progress loops depend on being able to do this.
133 const Node* node = that._node;
134 // Re-initialize everything, except _last.
135 _node = node;
136 _outcnt = node->_outcnt;
137 _del_tick = node->_del_tick;
138 }
139
140 void DUIterator::sample(const Node* node) {
141 DUIterator_Common::sample(node); // Initialize the assertion data.
142 _refresh_tick = 0; // No refreshes have happened, as yet.
143 }
144
145 void DUIterator::verify(const Node* node, bool at_end_ok) {
146 DUIterator_Common::verify(node, at_end_ok);
147 assert(_idx < node->_outcnt + (uint)at_end_ok, "idx in range");
148 }
149
150 void DUIterator::verify_increment() {
151 if (_refresh_tick & 1) {
152 // We have refreshed the index during this loop.
153 // Fix up _idx to meet asserts.
154 if (_idx > _outcnt) _idx = _outcnt;
155 }
156 verify(_node, true);
157 }
158
159 void DUIterator::verify_resync() {
160 // Note: We do not assert on _outcnt, because insertions are OK here.
161 DUIterator_Common::verify_resync();
162 // Make sure we are still in sync, possibly with no more out-edges:
163 verify(_node, true);
164 }
165
166 void DUIterator::reset(const DUIterator& that) {
167 if (this == &that) return; // self assignment is always a no-op
168 assert(that._refresh_tick == 0, "assign only the result of Node::outs()");
169 assert(that._idx == 0, "assign only the result of Node::outs()");
170 assert(_idx == that._idx, "already assigned _idx");
171 if (!_vdui) {
172 // We need to initialize everything, overwriting garbage values.
173 sample(that._node);
174 } else {
175 DUIterator_Common::reset(that);
176 if (_refresh_tick & 1) {
177 _refresh_tick++; // Clear the "was refreshed" flag.
178 }
179 assert(_refresh_tick < 2*100000, "DU iteration must converge quickly");
180 }
181 }
182
183 void DUIterator::refresh() {
184 DUIterator_Common::sample(_node); // Re-fetch assertion data.
185 _refresh_tick |= 1; // Set the "was refreshed" flag.
186 }
187
188 void DUIterator::verify_finish() {
189 // If the loop has killed the node, do not require it to re-run.
190 if (_node->_outcnt == 0) _refresh_tick &= ~1;
191 // If this assert triggers, it means that a loop used refresh_out_pos
192 // to re-synch an iteration index, but the loop did not correctly
193 // re-run itself, using a "while (progress)" construct.
194 // This iterator enforces the rule that you must keep trying the loop
195 // until it "runs clean" without any need for refreshing.
196 assert(!(_refresh_tick & 1), "the loop must run once with no refreshing");
197 }
198
199
200 void DUIterator_Fast::verify(const Node* node, bool at_end_ok) {
201 DUIterator_Common::verify(node, at_end_ok);
202 Node** out = node->_out;
203 uint cnt = node->_outcnt;
204 assert(cnt == _outcnt, "no insertions allowed");
205 assert(_outp >= out && _outp <= out + cnt - !at_end_ok, "outp in range");
206 // This last check is carefully designed to work for NO_OUT_ARRAY.
207 }
208
209 void DUIterator_Fast::verify_limit() {
210 const Node* node = _node;
211 verify(node, true);
212 assert(_outp == node->_out + node->_outcnt, "limit still correct");
213 }
214
215 void DUIterator_Fast::verify_resync() {
216 const Node* node = _node;
217 if (_outp == node->_out + _outcnt) {
218 // Note that the limit imax, not the pointer i, gets updated with the
219 // exact count of deletions. (For the pointer it's always "--i".)
220 assert(node->_outcnt+node->_del_tick == _outcnt+_del_tick, "no insertions allowed with deletion(s)");
221 // This is a limit pointer, with a name like "imax".
222 // Fudge the _last field so that the common assert will be happy.
223 _last = (Node*) node->_last_del;
224 DUIterator_Common::verify_resync();
225 } else {
226 assert(node->_outcnt < _outcnt, "no insertions allowed with deletion(s)");
227 // A normal internal pointer.
228 DUIterator_Common::verify_resync();
229 // Make sure we are still in sync, possibly with no more out-edges:
230 verify(node, true);
231 }
232 }
233
234 void DUIterator_Fast::verify_relimit(uint n) {
235 const Node* node = _node;
236 assert((int)n > 0, "use imax -= n only with a positive count");
237 // This must be a limit pointer, with a name like "imax".
238 assert(_outp == node->_out + node->_outcnt, "apply -= only to a limit (imax)");
239 // The reported number of deletions must match what the node saw.
240 assert(node->_del_tick == _del_tick + n, "must have deleted n edges");
241 // Fudge the _last field so that the common assert will be happy.
242 _last = (Node*) node->_last_del;
243 DUIterator_Common::verify_resync();
244 }
245
246 void DUIterator_Fast::reset(const DUIterator_Fast& that) {
247 assert(_outp == that._outp, "already assigned _outp");
248 DUIterator_Common::reset(that);
249 }
250
251 void DUIterator_Last::verify(const Node* node, bool at_end_ok) {
252 // at_end_ok means the _outp is allowed to underflow by 1
253 _outp += at_end_ok;
254 DUIterator_Fast::verify(node, at_end_ok); // check _del_tick, etc.
255 _outp -= at_end_ok;
256 assert(_outp == (node->_out + node->_outcnt) - 1, "pointer must point to end of nodes");
257 }
258
259 void DUIterator_Last::verify_limit() {
260 // Do not require the limit address to be resynched.
261 //verify(node, true);
262 assert(_outp == _node->_out, "limit still correct");
263 }
264
265 void DUIterator_Last::verify_step(uint num_edges) {
266 assert((int)num_edges > 0, "need non-zero edge count for loop progress");
267 _outcnt -= num_edges;
268 _del_tick += num_edges;
269 // Make sure we are still in sync, possibly with no more out-edges:
270 const Node* node = _node;
271 verify(node, true);
272 assert(node->_last_del == _last, "must have deleted the edge just produced");
273 }
274
275 #endif //OPTO_DU_ITERATOR_ASSERT
276
277
278 #endif //ASSERT
279
280
281 // This constant used to initialize _out may be any non-null value.
282 // The value null is reserved for the top node only.
283 #define NO_OUT_ARRAY ((Node**)-1)
284
285 // Out-of-line code from node constructors.
286 // Executed only when extra debug info. is being passed around.
287 static void init_node_notes(Compile* C, int idx, Node_Notes* nn) {
288 C->set_node_notes_at(idx, nn);
289 }
290
291 // Shared initialization code.
292 inline int Node::Init(int req) {
293 Compile* C = Compile::current();
294 int idx = C->next_unique();
295 NOT_PRODUCT(_igv_idx = C->next_igv_idx());
296
297 // Allocate memory for the necessary number of edges.
298 if (req > 0) {
299 // Allocate space for _in array to have double alignment.
300 _in = (Node **) ((char *) (C->node_arena()->AmallocWords(req * sizeof(void*))));
301 }
302 // If there are default notes floating around, capture them:
303 Node_Notes* nn = C->default_node_notes();
304 if (nn != nullptr) init_node_notes(C, idx, nn);
305
306 // Note: At this point, C is dead,
307 // and we begin to initialize the new Node.
308
309 _cnt = _max = req;
310 _outcnt = _outmax = 0;
311 _class_id = Class_Node;
312 _flags = 0;
313 _out = NO_OUT_ARRAY;
314 return idx;
315 }
316
317 //------------------------------Node-------------------------------------------
318 // Create a Node, with a given number of required edges.
319 Node::Node(uint req)
320 : _idx(Init(req))
321 #ifdef ASSERT
322 , _parse_idx(_idx)
323 #endif
324 {
325 assert( req < Compile::current()->max_node_limit() - NodeLimitFudgeFactor, "Input limit exceeded" );
326 DEBUG_ONLY( verify_construction() );
327 NOT_PRODUCT(nodes_created++);
328 if (req == 0) {
329 _in = nullptr;
330 } else {
331 Node** to = _in;
332 for(uint i = 0; i < req; i++) {
333 to[i] = nullptr;
334 }
335 }
336 }
337
338 //------------------------------Node-------------------------------------------
339 Node::Node(Node *n0)
340 : _idx(Init(1))
341 #ifdef ASSERT
342 , _parse_idx(_idx)
343 #endif
344 {
345 DEBUG_ONLY( verify_construction() );
346 NOT_PRODUCT(nodes_created++);
347 assert( is_not_dead(n0), "can not use dead node");
348 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
349 }
350
351 //------------------------------Node-------------------------------------------
352 Node::Node(Node *n0, Node *n1)
353 : _idx(Init(2))
354 #ifdef ASSERT
355 , _parse_idx(_idx)
356 #endif
357 {
358 DEBUG_ONLY( verify_construction() );
359 NOT_PRODUCT(nodes_created++);
360 assert( is_not_dead(n0), "can not use dead node");
361 assert( is_not_dead(n1), "can not use dead node");
362 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
363 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
364 }
365
366 //------------------------------Node-------------------------------------------
367 Node::Node(Node *n0, Node *n1, Node *n2)
368 : _idx(Init(3))
369 #ifdef ASSERT
370 , _parse_idx(_idx)
371 #endif
372 {
373 DEBUG_ONLY( verify_construction() );
374 NOT_PRODUCT(nodes_created++);
375 assert( is_not_dead(n0), "can not use dead node");
376 assert( is_not_dead(n1), "can not use dead node");
377 assert( is_not_dead(n2), "can not use dead node");
378 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
379 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
380 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
381 }
382
383 //------------------------------Node-------------------------------------------
384 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3)
385 : _idx(Init(4))
386 #ifdef ASSERT
387 , _parse_idx(_idx)
388 #endif
389 {
390 DEBUG_ONLY( verify_construction() );
391 NOT_PRODUCT(nodes_created++);
392 assert( is_not_dead(n0), "can not use dead node");
393 assert( is_not_dead(n1), "can not use dead node");
394 assert( is_not_dead(n2), "can not use dead node");
395 assert( is_not_dead(n3), "can not use dead node");
396 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
397 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
398 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
399 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
400 }
401
402 //------------------------------Node-------------------------------------------
403 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3, Node *n4)
404 : _idx(Init(5))
405 #ifdef ASSERT
406 , _parse_idx(_idx)
407 #endif
408 {
409 DEBUG_ONLY( verify_construction() );
410 NOT_PRODUCT(nodes_created++);
411 assert( is_not_dead(n0), "can not use dead node");
412 assert( is_not_dead(n1), "can not use dead node");
413 assert( is_not_dead(n2), "can not use dead node");
414 assert( is_not_dead(n3), "can not use dead node");
415 assert( is_not_dead(n4), "can not use dead node");
416 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
417 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
418 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
419 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
420 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
421 }
422
423 //------------------------------Node-------------------------------------------
424 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
425 Node *n4, Node *n5)
426 : _idx(Init(6))
427 #ifdef ASSERT
428 , _parse_idx(_idx)
429 #endif
430 {
431 DEBUG_ONLY( verify_construction() );
432 NOT_PRODUCT(nodes_created++);
433 assert( is_not_dead(n0), "can not use dead node");
434 assert( is_not_dead(n1), "can not use dead node");
435 assert( is_not_dead(n2), "can not use dead node");
436 assert( is_not_dead(n3), "can not use dead node");
437 assert( is_not_dead(n4), "can not use dead node");
438 assert( is_not_dead(n5), "can not use dead node");
439 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
440 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
441 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
442 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
443 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
444 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
445 }
446
447 //------------------------------Node-------------------------------------------
448 Node::Node(Node *n0, Node *n1, Node *n2, Node *n3,
449 Node *n4, Node *n5, Node *n6)
450 : _idx(Init(7))
451 #ifdef ASSERT
452 , _parse_idx(_idx)
453 #endif
454 {
455 DEBUG_ONLY( verify_construction() );
456 NOT_PRODUCT(nodes_created++);
457 assert( is_not_dead(n0), "can not use dead node");
458 assert( is_not_dead(n1), "can not use dead node");
459 assert( is_not_dead(n2), "can not use dead node");
460 assert( is_not_dead(n3), "can not use dead node");
461 assert( is_not_dead(n4), "can not use dead node");
462 assert( is_not_dead(n5), "can not use dead node");
463 assert( is_not_dead(n6), "can not use dead node");
464 _in[0] = n0; if (n0 != nullptr) n0->add_out((Node *)this);
465 _in[1] = n1; if (n1 != nullptr) n1->add_out((Node *)this);
466 _in[2] = n2; if (n2 != nullptr) n2->add_out((Node *)this);
467 _in[3] = n3; if (n3 != nullptr) n3->add_out((Node *)this);
468 _in[4] = n4; if (n4 != nullptr) n4->add_out((Node *)this);
469 _in[5] = n5; if (n5 != nullptr) n5->add_out((Node *)this);
470 _in[6] = n6; if (n6 != nullptr) n6->add_out((Node *)this);
471 }
472
473 #ifdef __clang__
474 #pragma clang diagnostic pop
475 #endif
476
477
478 //------------------------------clone------------------------------------------
479 // Clone a Node.
480 Node *Node::clone() const {
481 Compile* C = Compile::current();
482 uint s = size_of(); // Size of inherited Node
483 Node *n = (Node*)C->node_arena()->AmallocWords(size_of() + _max*sizeof(Node*));
484 Copy::conjoint_words_to_lower((HeapWord*)this, (HeapWord*)n, s);
485 // Set the new input pointer array
486 n->_in = (Node**)(((char*)n)+s);
487 // Cannot share the old output pointer array, so kill it
488 n->_out = NO_OUT_ARRAY;
489 // And reset the counters to 0
490 n->_outcnt = 0;
491 n->_outmax = 0;
492 // Unlock this guy, since he is not in any hash table.
493 DEBUG_ONLY(n->_hash_lock = 0);
494 // Walk the old node's input list to duplicate its edges
495 uint i;
496 for( i = 0; i < len(); i++ ) {
497 Node *x = in(i);
498 n->_in[i] = x;
499 if (x != nullptr) x->add_out(n);
500 }
501 if (is_macro()) {
502 C->add_macro_node(n);
503 }
504 if (is_expensive()) {
505 C->add_expensive_node(n);
506 }
507 if (is_ReachabilityFence()) {
508 C->add_reachability_fence(n->as_ReachabilityFence());
509 }
510 if (for_post_loop_opts_igvn()) {
511 // Don't add cloned node to Compile::_for_post_loop_opts_igvn list automatically.
512 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
513 n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
514 }
515 if (for_merge_stores_igvn()) {
516 // Don't add cloned node to Compile::_for_merge_stores_igvn list automatically.
517 // If it is applicable, it will happen anyway when the cloned node is registered with IGVN.
518 n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
519 }
520 if (n->is_ParsePredicate()) {
521 C->add_parse_predicate(n->as_ParsePredicate());
522 }
523 if (n->is_OpaqueTemplateAssertionPredicate()) {
524 C->add_template_assertion_predicate_opaque(n->as_OpaqueTemplateAssertionPredicate());
525 }
526
527 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
528 bs->register_potential_barrier_node(n);
529
530 n->set_idx(C->next_unique()); // Get new unique index as well
531 NOT_PRODUCT(n->_igv_idx = C->next_igv_idx());
532 DEBUG_ONLY( n->verify_construction() );
533 NOT_PRODUCT(nodes_created++);
534 // Do not patch over the debug_idx of a clone, because it makes it
535 // impossible to break on the clone's moment of creation.
536 //DEBUG_ONLY( n->set_debug_idx( debug_idx() ) );
537
538 C->copy_node_notes_to(n, (Node*) this);
539
540 // MachNode clone
541 uint nopnds;
542 if (this->is_Mach() && (nopnds = this->as_Mach()->num_opnds()) > 0) {
543 MachNode *mach = n->as_Mach();
544 MachNode *mthis = this->as_Mach();
545 // Get address of _opnd_array.
546 // It should be the same offset since it is the clone of this node.
547 MachOper **from = mthis->_opnds;
548 MachOper **to = (MachOper **)((size_t)(&mach->_opnds) +
549 pointer_delta((const void*)from,
550 (const void*)(&mthis->_opnds), 1));
551 mach->_opnds = to;
552 for ( uint i = 0; i < nopnds; ++i ) {
553 to[i] = from[i]->clone();
554 }
555 }
556 if (this->is_MachProj()) {
557 // MachProjNodes contain register masks that may contain pointers to
558 // externally allocated memory. Make sure to use a proper constructor
559 // instead of just shallowly copying.
560 MachProjNode* mach = n->as_MachProj();
561 MachProjNode* mthis = this->as_MachProj();
562 new (&mach->_rout) RegMask(mthis->_rout);
563 }
564 if (n->is_Call()) {
565 // CallGenerator is linked to the original node.
566 CallGenerator* cg = n->as_Call()->generator();
567 if (cg != nullptr) {
568 CallGenerator* cloned_cg = cg->with_call_node(n->as_Call());
569 n->as_Call()->set_generator(cloned_cg);
570 }
571 }
572 if (n->is_SafePoint()) {
573 // Scalar replacement and macro expansion might modify the JVMState.
574 // Clone it to make sure it's not shared between SafePointNodes.
575 n->as_SafePoint()->clone_jvms(C);
576 n->as_SafePoint()->clone_replaced_nodes();
577 }
578 Compile::current()->record_modified_node(n);
579 return n; // Return the clone
580 }
581
582 //---------------------------setup_is_top--------------------------------------
583 // Call this when changing the top node, to reassert the invariants
584 // required by Node::is_top. See Compile::set_cached_top_node.
585 void Node::setup_is_top() {
586 if (this == (Node*)Compile::current()->top()) {
587 // This node has just become top. Kill its out array.
588 _outcnt = _outmax = 0;
589 _out = nullptr; // marker value for top
590 assert(is_top(), "must be top");
591 } else {
592 if (_out == nullptr) _out = NO_OUT_ARRAY;
593 assert(!is_top(), "must not be top");
594 }
595 }
596
597 //------------------------------~Node------------------------------------------
598 // Fancy destructor; eagerly attempt to reclaim Node numberings and storage
599 void Node::destruct(PhaseValues* phase) {
600 Compile* compile = (phase != nullptr) ? phase->C : Compile::current();
601 if (phase != nullptr && phase->is_IterGVN()) {
602 phase->is_IterGVN()->_worklist.remove(this);
603 }
604 // If this is the most recently created node, reclaim its index. Otherwise,
605 // record the node as dead to keep liveness information accurate.
606 if ((uint)_idx+1 == compile->unique()) {
607 compile->set_unique(compile->unique()-1);
608 } else {
609 compile->record_dead_node(_idx);
610 }
611 // Clear debug info:
612 Node_Notes* nn = compile->node_notes_at(_idx);
613 if (nn != nullptr) nn->clear();
614 // Walk the input array, freeing the corresponding output edges
615 _cnt = _max; // forget req/prec distinction
616 uint i;
617 for( i = 0; i < _max; i++ ) {
618 set_req(i, nullptr);
619 //assert(def->out(def->outcnt()-1) == (Node *)this,"bad def-use hacking in reclaim");
620 }
621 assert(outcnt() == 0, "deleting a node must not leave a dangling use");
622
623 if (is_macro()) {
624 compile->remove_macro_node(this);
625 }
626 if (is_expensive()) {
627 compile->remove_expensive_node(this);
628 }
629 if (is_ReachabilityFence()) {
630 compile->remove_reachability_fence(as_ReachabilityFence());
631 }
632 if (is_OpaqueTemplateAssertionPredicate()) {
633 compile->remove_template_assertion_predicate_opaque(as_OpaqueTemplateAssertionPredicate());
634 }
635 if (is_ParsePredicate()) {
636 compile->remove_parse_predicate(as_ParsePredicate());
637 }
638 if (for_post_loop_opts_igvn()) {
639 compile->remove_from_post_loop_opts_igvn(this);
640 }
641 if (for_merge_stores_igvn()) {
642 compile->remove_from_merge_stores_igvn(this);
643 }
644
645 if (is_SafePoint()) {
646 as_SafePoint()->delete_replaced_nodes();
647
648 if (is_CallStaticJava()) {
649 compile->remove_unstable_if_trap(as_CallStaticJava(), false);
650 }
651 }
652 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
653 bs->unregister_potential_barrier_node(this);
654
655 // See if the input array was allocated just prior to the object
656 int edge_size = _max*sizeof(void*);
657 int out_edge_size = _outmax*sizeof(void*);
658 char *in_array = ((char*)_in);
659 char *edge_end = in_array + edge_size;
660 char *out_array = (char*)(_out == NO_OUT_ARRAY? nullptr: _out);
661 int node_size = size_of();
662
663 #ifdef ASSERT
664 // We will not actually delete the storage, but we'll make the node unusable.
665 compile->remove_modified_node(this);
666 *(address*)this = badAddress; // smash the C++ vtbl, probably
667 _in = _out = (Node**) badAddress;
668 _max = _cnt = _outmax = _outcnt = 0;
669 #endif
670
671 // Free the output edge array
672 if (out_edge_size > 0) {
673 compile->node_arena()->Afree(out_array, out_edge_size);
674 }
675
676 // Free the input edge array and the node itself
677 if( edge_end == (char*)this ) {
678 // It was; free the input array and object all in one hit
679 #ifndef ASSERT
680 compile->node_arena()->Afree(in_array, edge_size+node_size);
681 #endif
682 } else {
683 // Free just the input array
684 compile->node_arena()->Afree(in_array, edge_size);
685
686 // Free just the object
687 #ifndef ASSERT
688 compile->node_arena()->Afree(this, node_size);
689 #endif
690 }
691 }
692
693 // Resize input or output array to grow it to the next larger power-of-2 bigger
694 // than len.
695 void Node::resize_array(Node**& array, node_idx_t& max_size, uint len, bool needs_clearing) {
696 Arena* arena = Compile::current()->node_arena();
697 uint new_max = max_size;
698 if (new_max == 0) {
699 max_size = 4;
700 array = (Node**)arena->Amalloc(4 * sizeof(Node*));
701 if (needs_clearing) {
702 array[0] = nullptr;
703 array[1] = nullptr;
704 array[2] = nullptr;
705 array[3] = nullptr;
706 }
707 return;
708 }
709 new_max = next_power_of_2(len);
710 assert(needs_clearing || (array != nullptr && array != NO_OUT_ARRAY), "out must have sensible value");
711 array = (Node**)arena->Arealloc(array, max_size * sizeof(Node*), new_max * sizeof(Node*));
712 if (needs_clearing) {
713 Copy::zero_to_bytes(&array[max_size], (new_max - max_size) * sizeof(Node*)); // null all new space
714 }
715 max_size = new_max; // Record new max length
716 // This assertion makes sure that Node::_max is wide enough to
717 // represent the numerical value of new_max.
718 assert(max_size > len, "int width of _max or _outmax is too small");
719 }
720
721 //------------------------------grow-------------------------------------------
722 // Grow the input array, making space for more edges
723 void Node::grow(uint len) {
724 resize_array(_in, _max, len, true);
725 }
726
727 //-----------------------------out_grow----------------------------------------
728 // Grow the input array, making space for more edges
729 void Node::out_grow(uint len) {
730 assert(!is_top(), "cannot grow a top node's out array");
731 resize_array(_out, _outmax, len, false);
732 }
733
734 #ifdef ASSERT
735 //------------------------------is_dead----------------------------------------
736 bool Node::is_dead() const {
737 // Mach and pinch point nodes may look like dead.
738 if( is_top() || is_Mach() || (Opcode() == Op_Node && _outcnt > 0) )
739 return false;
740 for( uint i = 0; i < _max; i++ )
741 if( _in[i] != nullptr )
742 return false;
743 return true;
744 }
745
746 bool Node::is_not_dead(const Node* n) {
747 return n == nullptr || !PhaseIterGVN::is_verify_def_use() || !(n->is_dead());
748 }
749
750 bool Node::is_reachable_from_root() const {
751 ResourceMark rm;
752 Unique_Node_List wq;
753 wq.push((Node*)this);
754 RootNode* root = Compile::current()->root();
755 for (uint i = 0; i < wq.size(); i++) {
756 Node* m = wq.at(i);
757 if (m == root) {
758 return true;
759 }
760 for (DUIterator_Fast jmax, j = m->fast_outs(jmax); j < jmax; j++) {
761 Node* u = m->fast_out(j);
762 wq.push(u);
763 }
764 }
765 return false;
766 }
767 #endif
768
769 //------------------------------is_unreachable---------------------------------
770 bool Node::is_unreachable(PhaseIterGVN &igvn) const {
771 assert(!is_Mach(), "doesn't work with MachNodes");
772 return outcnt() == 0 || igvn.type(this) == Type::TOP || (in(0) != nullptr && in(0)->is_top());
773 }
774
775 //------------------------------add_req----------------------------------------
776 // Add a new required input at the end
777 void Node::add_req( Node *n ) {
778 assert( is_not_dead(n), "can not use dead node");
779
780 // Look to see if I can move precedence down one without reallocating
781 if( (_cnt >= _max) || (in(_max-1) != nullptr) )
782 grow( _max+1 );
783
784 // Find a precedence edge to move
785 if( in(_cnt) != nullptr ) { // Next precedence edge is busy?
786 uint i;
787 for( i=_cnt; i<_max; i++ )
788 if( in(i) == nullptr ) // Find the null at end of prec edge list
789 break; // There must be one, since we grew the array
790 _in[i] = in(_cnt); // Move prec over, making space for req edge
791 }
792 _in[_cnt++] = n; // Stuff over old prec edge
793 if (n != nullptr) n->add_out((Node *)this);
794 Compile::current()->record_modified_node(this);
795 }
796
797 //---------------------------add_req_batch-------------------------------------
798 // Add a new required input at the end
799 void Node::add_req_batch( Node *n, uint m ) {
800 assert( is_not_dead(n), "can not use dead node");
801 // check various edge cases
802 if ((int)m <= 1) {
803 assert((int)m >= 0, "oob");
804 if (m != 0) add_req(n);
805 return;
806 }
807
808 // Look to see if I can move precedence down one without reallocating
809 if( (_cnt+m) > _max || _in[_max-m] )
810 grow( _max+m );
811
812 // Find a precedence edge to move
813 if( _in[_cnt] != nullptr ) { // Next precedence edge is busy?
814 uint i;
815 for( i=_cnt; i<_max; i++ )
816 if( _in[i] == nullptr ) // Find the null at end of prec edge list
817 break; // There must be one, since we grew the array
818 // Slide all the precs over by m positions (assume #prec << m).
819 Copy::conjoint_words_to_higher((HeapWord*)&_in[_cnt], (HeapWord*)&_in[_cnt+m], ((i-_cnt)*sizeof(Node*)));
820 }
821
822 // Stuff over the old prec edges
823 for(uint i=0; i<m; i++ ) {
824 _in[_cnt++] = n;
825 }
826
827 // Insert multiple out edges on the node.
828 if (n != nullptr && !n->is_top()) {
829 for(uint i=0; i<m; i++ ) {
830 n->add_out((Node *)this);
831 }
832 }
833 Compile::current()->record_modified_node(this);
834 }
835
836 //------------------------------del_req----------------------------------------
837 // Delete the required edge and compact the edge array
838 void Node::del_req( uint idx ) {
839 assert( idx < _cnt, "oob");
840 assert( !VerifyHashTableKeys || _hash_lock == 0,
841 "remove node from hash table before modifying it");
842 // First remove corresponding def-use edge
843 Node *n = in(idx);
844 if (n != nullptr) n->del_out((Node *)this);
845 _in[idx] = in(--_cnt); // Compact the array
846 // Avoid spec violation: Gap in prec edges.
847 close_prec_gap_at(_cnt);
848 Compile::current()->record_modified_node(this);
849 }
850
851 //------------------------------del_req_ordered--------------------------------
852 // Delete the required edge and compact the edge array with preserved order
853 void Node::del_req_ordered( uint idx ) {
854 assert( idx < _cnt, "oob");
855 assert( !VerifyHashTableKeys || _hash_lock == 0,
856 "remove node from hash table before modifying it");
857 // First remove corresponding def-use edge
858 Node *n = in(idx);
859 if (n != nullptr) n->del_out((Node *)this);
860 if (idx < --_cnt) { // Not last edge ?
861 Copy::conjoint_words_to_lower((HeapWord*)&_in[idx+1], (HeapWord*)&_in[idx], ((_cnt-idx)*sizeof(Node*)));
862 }
863 // Avoid spec violation: Gap in prec edges.
864 close_prec_gap_at(_cnt);
865 Compile::current()->record_modified_node(this);
866 }
867
868 //------------------------------ins_req----------------------------------------
869 // Insert a new required input at the end
870 void Node::ins_req( uint idx, Node *n ) {
871 assert( is_not_dead(n), "can not use dead node");
872 add_req(nullptr); // Make space
873 assert( idx < _max, "Must have allocated enough space");
874 // Slide over
875 if(_cnt-idx-1 > 0) {
876 Copy::conjoint_words_to_higher((HeapWord*)&_in[idx], (HeapWord*)&_in[idx+1], ((_cnt-idx-1)*sizeof(Node*)));
877 }
878 _in[idx] = n; // Stuff over old required edge
879 if (n != nullptr) n->add_out((Node *)this); // Add reciprocal def-use edge
880 Compile::current()->record_modified_node(this);
881 }
882
883 //-----------------------------find_edge---------------------------------------
884 int Node::find_edge(Node* n) {
885 for (uint i = 0; i < len(); i++) {
886 if (_in[i] == n) return i;
887 }
888 return -1;
889 }
890
891 //----------------------------replace_edge-------------------------------------
892 int Node::replace_edge(Node* old, Node* neww, PhaseGVN* gvn) {
893 if (old == neww) return 0; // nothing to do
894 uint nrep = 0;
895 for (uint i = 0; i < len(); i++) {
896 if (in(i) == old) {
897 if (i < req()) {
898 if (gvn != nullptr) {
899 set_req_X(i, neww, gvn);
900 } else {
901 set_req(i, neww);
902 }
903 } else {
904 assert(gvn == nullptr || gvn->is_IterGVN() == nullptr, "no support for igvn here");
905 assert(find_prec_edge(neww) == -1, "spec violation: duplicated prec edge (node %d -> %d)", _idx, neww->_idx);
906 set_prec(i, neww);
907 }
908 nrep++;
909 }
910 }
911 return nrep;
912 }
913
914 /**
915 * Replace input edges in the range pointing to 'old' node.
916 */
917 int Node::replace_edges_in_range(Node* old, Node* neww, int start, int end, PhaseGVN* gvn) {
918 if (old == neww) return 0; // nothing to do
919 uint nrep = 0;
920 for (int i = start; i < end; i++) {
921 if (in(i) == old) {
922 set_req_X(i, neww, gvn);
923 nrep++;
924 }
925 }
926 return nrep;
927 }
928
929 //-------------------------disconnect_inputs-----------------------------------
930 // null out all inputs to eliminate incoming Def-Use edges.
931 void Node::disconnect_inputs(Compile* C) {
932 // the layout of Node::_in
933 // r: a required input, null is allowed
934 // p: a precedence, null values are all at the end
935 // -----------------------------------
936 // |r|...|r|p|...|p|null|...|null|
937 // | |
938 // req() len()
939 // -----------------------------------
940 for (uint i = 0; i < req(); ++i) {
941 if (in(i) != nullptr) {
942 set_req(i, nullptr);
943 }
944 }
945
946 // Remove precedence edges if any exist
947 // Note: Safepoints may have precedence edges, even during parsing
948 for (uint i = len(); i > req(); ) {
949 rm_prec(--i); // no-op if _in[i] is null
950 }
951
952 #ifdef ASSERT
953 // sanity check
954 for (uint i = 0; i < len(); ++i) {
955 assert(_in[i] == nullptr, "disconnect_inputs() failed!");
956 }
957 #endif
958
959 // Node::destruct requires all out edges be deleted first
960 // DEBUG_ONLY(destruct();) // no reuse benefit expected
961 C->record_dead_node(_idx);
962 }
963
964 //-----------------------------uncast---------------------------------------
965 // %%% Temporary, until we sort out CheckCastPP vs. CastPP.
966 // Strip away casting. (It is depth-limited.)
967 // Optionally, keep casts with dependencies.
968 Node* Node::uncast(bool keep_deps) const {
969 // Should be inline:
970 //return is_ConstraintCast() ? uncast_helper(this) : (Node*) this;
971 if (is_ConstraintCast()) {
972 return uncast_helper(this, keep_deps);
973 } else {
974 return (Node*) this;
975 }
976 }
977
978 // Find out of current node that matches opcode.
979 Node* Node::find_out_with(int opcode) {
980 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
981 Node* use = fast_out(i);
982 if (use->Opcode() == opcode) {
983 return use;
984 }
985 }
986 return nullptr;
987 }
988
989 // Return true if the current node has an out that matches opcode.
990 bool Node::has_out_with(int opcode) {
991 return (find_out_with(opcode) != nullptr);
992 }
993
994 // Return true if the current node has an out that matches any of the opcodes.
995 bool Node::has_out_with(int opcode1, int opcode2, int opcode3, int opcode4) {
996 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
997 int opcode = fast_out(i)->Opcode();
998 if (opcode == opcode1 || opcode == opcode2 || opcode == opcode3 || opcode == opcode4) {
999 return true;
1000 }
1001 }
1002 return false;
1003 }
1004
1005
1006 //---------------------------uncast_helper-------------------------------------
1007 Node* Node::uncast_helper(const Node* p, bool keep_deps) {
1008 #ifdef ASSERT
1009 // If we end up traversing more nodes than we actually have,
1010 // it is definitely an infinite loop.
1011 uint max_depth = Compile::current()->unique();
1012 uint depth_count = 0;
1013 const Node* orig_p = p;
1014 #endif
1015
1016 while (true) {
1017 #ifdef ASSERT
1018 if (depth_count++ >= max_depth) {
1019 orig_p->dump(4);
1020 if (p != orig_p) {
1021 p->dump(1);
1022 }
1023 fatal("infinite loop in Node::uncast_helper");
1024 }
1025 #endif
1026 if (p == nullptr || p->req() != 2) {
1027 break;
1028 } else if (p->is_ConstraintCast()) {
1029 if (keep_deps && p->as_ConstraintCast()->carry_dependency()) {
1030 break; // stop at casts with dependencies
1031 }
1032 p = p->in(1);
1033 } else {
1034 break;
1035 }
1036 }
1037 return (Node*) p;
1038 }
1039
1040 //------------------------------add_prec---------------------------------------
1041 // Add a new precedence input. Precedence inputs are unordered, with
1042 // duplicates removed and nulls packed down at the end.
1043 void Node::add_prec( Node *n ) {
1044 assert( is_not_dead(n), "can not use dead node");
1045
1046 // Check for null at end
1047 if( _cnt >= _max || in(_max-1) )
1048 grow( _max+1 );
1049
1050 // Find a precedence edge to move
1051 uint i = _cnt;
1052 while( in(i) != nullptr ) {
1053 if (in(i) == n) return; // Avoid spec violation: duplicated prec edge.
1054 i++;
1055 }
1056 _in[i] = n; // Stuff prec edge over null
1057 if ( n != nullptr) n->add_out((Node *)this); // Add mirror edge
1058
1059 #ifdef ASSERT
1060 while ((++i)<_max) { assert(_in[i] == nullptr, "spec violation: Gap in prec edges (node %d)", _idx); }
1061 #endif
1062 Compile::current()->record_modified_node(this);
1063 }
1064
1065 //------------------------------rm_prec----------------------------------------
1066 // Remove a precedence input. Precedence inputs are unordered, with
1067 // duplicates removed and nulls packed down at the end.
1068 void Node::rm_prec( uint j ) {
1069 assert(j < _max, "oob: i=%d, _max=%d", j, _max);
1070 assert(j >= _cnt, "not a precedence edge");
1071 if (_in[j] == nullptr) return; // Avoid spec violation: Gap in prec edges.
1072 _in[j]->del_out((Node *)this);
1073 close_prec_gap_at(j);
1074 Compile::current()->record_modified_node(this);
1075 }
1076
1077 //------------------------------size_of----------------------------------------
1078 uint Node::size_of() const { return sizeof(*this); }
1079
1080 //------------------------------ideal_reg--------------------------------------
1081 uint Node::ideal_reg() const { return 0; }
1082
1083 //------------------------------jvms-------------------------------------------
1084 JVMState* Node::jvms() const { return nullptr; }
1085
1086 #ifdef ASSERT
1087 //------------------------------jvms-------------------------------------------
1088 bool Node::verify_jvms(const JVMState* using_jvms) const {
1089 for (JVMState* jvms = this->jvms(); jvms != nullptr; jvms = jvms->caller()) {
1090 if (jvms == using_jvms) return true;
1091 }
1092 return false;
1093 }
1094
1095 //------------------------------init_NodeProperty------------------------------
1096 void Node::init_NodeProperty() {
1097 assert(_max_classes <= max_juint, "too many NodeProperty classes");
1098 assert(max_flags() <= max_juint, "too many NodeProperty flags");
1099 }
1100
1101 //-----------------------------max_flags---------------------------------------
1102 juint Node::max_flags() {
1103 return (PD::_last_flag << 1) - 1; // allow flags combination
1104 }
1105 #endif
1106
1107 //------------------------------format-----------------------------------------
1108 // Print as assembly
1109 void Node::format( PhaseRegAlloc *, outputStream *st ) const {}
1110 //------------------------------emit-------------------------------------------
1111 // Emit bytes using C2_MacroAssembler
1112 void Node::emit(C2_MacroAssembler *masm, PhaseRegAlloc *ra_) const {}
1113 //------------------------------size-------------------------------------------
1114 // Size of instruction in bytes
1115 uint Node::size(PhaseRegAlloc *ra_) const { return 0; }
1116
1117 //------------------------------CFG Construction-------------------------------
1118 // Nodes that end basic blocks, e.g. IfTrue/IfFalse, JumpProjNode, Root,
1119 // Goto and Return.
1120 const Node *Node::is_block_proj() const { return nullptr; }
1121
1122 // Minimum guaranteed type
1123 const Type *Node::bottom_type() const { return Type::BOTTOM; }
1124
1125
1126 //------------------------------raise_bottom_type------------------------------
1127 // Get the worst-case Type output for this Node.
1128 void Node::raise_bottom_type(const Type* new_type) {
1129 if (is_Type()) {
1130 TypeNode *n = this->as_Type();
1131 if (VerifyAliases) {
1132 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1133 }
1134 n->set_type(new_type);
1135 } else if (is_Load()) {
1136 LoadNode *n = this->as_Load();
1137 if (VerifyAliases) {
1138 assert(new_type->higher_equal_speculative(n->type()), "new type must refine old type");
1139 }
1140 n->set_type(new_type);
1141 }
1142 }
1143
1144 //------------------------------Identity---------------------------------------
1145 // Return a node that the given node is equivalent to.
1146 Node* Node::Identity(PhaseGVN* phase) {
1147 return this; // Default to no identities
1148 }
1149
1150 //------------------------------Value------------------------------------------
1151 // Compute a new Type for a node using the Type of the inputs.
1152 const Type* Node::Value(PhaseGVN* phase) const {
1153 return bottom_type(); // Default to worst-case Type
1154 }
1155
1156 //------------------------------Ideal------------------------------------------
1157 //
1158 // 'Idealize' the graph rooted at this Node.
1159 //
1160 // In order to be efficient and flexible there are some subtle invariants
1161 // these Ideal calls need to hold. Some of the flag bits for '-XX:VerifyIterativeGVN'
1162 // can help with validating these invariants, although they are too slow to have on by default:
1163 // - '-XX:VerifyIterativeGVN=1' checks the def-use info
1164 // - '-XX:VerifyIterativeGVN=100000' checks the return value
1165 // If you are hacking an Ideal call, be sure to use these.
1166 //
1167 // The Ideal call almost arbitrarily reshape the graph rooted at the 'this'
1168 // pointer. If ANY change is made, it must return the root of the reshaped
1169 // graph - even if the root is the same Node. Example: swapping the inputs
1170 // to an AddINode gives the same answer and same root, but you still have to
1171 // return the 'this' pointer instead of null. If the node was already dead
1172 // before the Ideal call, this rule does not apply, and it is fine to return
1173 // nullptr even if modifications were made.
1174 //
1175 // You cannot return an OLD Node, except for the 'this' pointer. Use the
1176 // Identity call to return an old Node; basically if Identity can find
1177 // another Node have the Ideal call make no change and return null.
1178 // Example: AddINode::Ideal must check for add of zero; in this case it
1179 // returns null instead of doing any graph reshaping.
1180 //
1181 // You cannot modify any old Nodes except for the 'this' pointer. Due to
1182 // sharing there may be other users of the old Nodes relying on their current
1183 // semantics. Modifying them will break the other users.
1184 // Example: when reshape "(X+3)+4" into "X+7" you must leave the Node for
1185 // "X+3" unchanged in case it is shared.
1186 //
1187 // If you modify the 'this' pointer's inputs, you should use
1188 // 'set_req'. If you are making a new Node (either as the new root or
1189 // some new internal piece) you may use 'init_req' to set the initial
1190 // value. You can make a new Node with either 'new' or 'clone'. In
1191 // either case, def-use info is correctly maintained.
1192 //
1193 // Example: reshape "(X+3)+4" into "X+7":
1194 // set_req(1, in(1)->in(1));
1195 // set_req(2, phase->intcon(7));
1196 // return this;
1197 // Example: reshape "X*4" into "X<<2"
1198 // return new LShiftINode(in(1), phase->intcon(2));
1199 //
1200 // You must call 'phase->transform(X)' on any new Nodes X you make, except
1201 // for the returned root node. Example: reshape "X*31" with "(X<<5)-X".
1202 // Node *shift=phase->transform(new LShiftINode(in(1),phase->intcon(5)));
1203 // return new AddINode(shift, in(1));
1204 //
1205 // When making a Node for a constant use 'phase->makecon' or 'phase->intcon'.
1206 // These forms are faster than 'phase->transform(new ConNode())' and Do
1207 // The Right Thing with def-use info.
1208 //
1209 // You cannot bury the 'this' Node inside of a graph reshape. If the reshaped
1210 // graph uses the 'this' Node it must be the root. If you want a Node with
1211 // the same Opcode as the 'this' pointer use 'clone'.
1212 //
1213 Node *Node::Ideal(PhaseGVN *phase, bool can_reshape) {
1214 return nullptr; // Default to being Ideal already
1215 }
1216
1217 // Some nodes have specific Ideal subgraph transformations only if they are
1218 // unique users of specific nodes. Such nodes should be put on IGVN worklist
1219 // for the transformations to happen.
1220 bool Node::has_special_unique_user() const {
1221 assert(outcnt() == 1, "match only for unique out");
1222 Node* n = unique_out();
1223 int op = Opcode();
1224 if (this->is_Store()) {
1225 // Condition for back-to-back stores folding.
1226 return n->Opcode() == op && n->in(MemNode::Memory) == this;
1227 } else if ((this->is_Load() || this->is_DecodeN() || this->is_Phi() || this->is_Con()) && n->Opcode() == Op_MemBarAcquire) {
1228 // Condition for removing an unused LoadNode or DecodeNNode from the MemBarAcquire precedence input
1229 return true;
1230 } else if (this->is_Load() && n->is_Move()) {
1231 // Condition for MoveX2Y (LoadX mem) => LoadY mem
1232 return true;
1233 } else if (op == Op_AddL) {
1234 // Condition for convL2I(addL(x,y)) ==> addI(convL2I(x),convL2I(y))
1235 return n->Opcode() == Op_ConvL2I && n->in(1) == this;
1236 } else if (op == Op_SubI || op == Op_SubL) {
1237 // Condition for subI(x,subI(y,z)) ==> subI(addI(x,z),y)
1238 return n->Opcode() == op && n->in(2) == this;
1239 } else if (is_If() && (n->is_IfFalse() || n->is_IfTrue())) {
1240 // See IfProjNode::Identity()
1241 return true;
1242 } else if ((is_IfFalse() || is_IfTrue()) && n->is_If()) {
1243 // See IfNode::fold_compares
1244 return true;
1245 } else if (n->Opcode() == Op_XorV || n->Opcode() == Op_XorVMask) {
1246 // Condition for XorVMask(VectorMaskCmp(x,y,cond), MaskAll(true)) ==> VectorMaskCmp(x,y,ncond)
1247 return true;
1248 } else {
1249 return false;
1250 }
1251 };
1252
1253 //--------------------------find_exact_control---------------------------------
1254 // Skip Proj and CatchProj nodes chains. Check for Null and Top.
1255 Node* Node::find_exact_control(Node* ctrl) {
1256 if (ctrl == nullptr && this->is_Region())
1257 ctrl = this->as_Region()->is_copy();
1258
1259 if (ctrl != nullptr && ctrl->is_CatchProj()) {
1260 if (ctrl->as_CatchProj()->_con == CatchProjNode::fall_through_index)
1261 ctrl = ctrl->in(0);
1262 if (ctrl != nullptr && !ctrl->is_top())
1263 ctrl = ctrl->in(0);
1264 }
1265
1266 if (ctrl != nullptr && ctrl->is_Proj())
1267 ctrl = ctrl->in(0);
1268
1269 return ctrl;
1270 }
1271
1272 //--------------------------dominates------------------------------------------
1273 // Helper function for MemNode::all_controls_dominate().
1274 // Check if 'this' control node dominates or equal to 'sub' control node.
1275 // We already know that if any path back to Root or Start reaches 'this',
1276 // then all paths so, so this is a simple search for one example,
1277 // not an exhaustive search for a counterexample.
1278 Node::DomResult Node::dominates(Node* sub, Node_List &nlist) {
1279 assert(this->is_CFG(), "expecting control");
1280 assert(sub != nullptr && sub->is_CFG(), "expecting control");
1281
1282 // detect dead cycle without regions
1283 int iterations_without_region_limit = DominatorSearchLimit;
1284
1285 Node* orig_sub = sub;
1286 Node* dom = this;
1287 bool met_dom = false;
1288 nlist.clear();
1289
1290 // Walk 'sub' backward up the chain to 'dom', watching for regions.
1291 // After seeing 'dom', continue up to Root or Start.
1292 // If we hit a region (backward split point), it may be a loop head.
1293 // Keep going through one of the region's inputs. If we reach the
1294 // same region again, go through a different input. Eventually we
1295 // will either exit through the loop head, or give up.
1296 // (If we get confused, break out and return a conservative 'false'.)
1297 while (sub != nullptr) {
1298 if (sub->is_top()) {
1299 // Conservative answer for dead code.
1300 return DomResult::EncounteredDeadCode;
1301 }
1302 if (sub == dom) {
1303 if (nlist.size() == 0) {
1304 // No Region nodes except loops were visited before and the EntryControl
1305 // path was taken for loops: it did not walk in a cycle.
1306 return DomResult::Dominate;
1307 } else if (met_dom) {
1308 break; // already met before: walk in a cycle
1309 } else {
1310 // Region nodes were visited. Continue walk up to Start or Root
1311 // to make sure that it did not walk in a cycle.
1312 met_dom = true; // first time meet
1313 iterations_without_region_limit = DominatorSearchLimit; // Reset
1314 }
1315 }
1316 if (sub->is_Start() || sub->is_Root()) {
1317 // Success if we met 'dom' along a path to Start or Root.
1318 // We assume there are no alternative paths that avoid 'dom'.
1319 // (This assumption is up to the caller to ensure!)
1320 return met_dom ? DomResult::Dominate : DomResult::NotDominate;
1321 }
1322 Node* up = sub->in(0);
1323 // Normalize simple pass-through regions and projections:
1324 up = sub->find_exact_control(up);
1325 // If sub == up, we found a self-loop. Try to push past it.
1326 if (sub == up && sub->is_Loop()) {
1327 // Take loop entry path on the way up to 'dom'.
1328 up = sub->in(1); // in(LoopNode::EntryControl);
1329 } else if (sub == up && sub->is_Region() && sub->req() == 2) {
1330 // Take in(1) path on the way up to 'dom' for regions with only one input
1331 up = sub->in(1);
1332 } else if (sub == up && sub->is_Region()) {
1333 // Try both paths for Regions with 2 input paths (it may be a loop head).
1334 // It could give conservative 'false' answer without information
1335 // which region's input is the entry path.
1336 iterations_without_region_limit = DominatorSearchLimit; // Reset
1337
1338 bool region_was_visited_before = false;
1339 // Was this Region node visited before?
1340 // If so, we have reached it because we accidentally took a
1341 // loop-back edge from 'sub' back into the body of the loop,
1342 // and worked our way up again to the loop header 'sub'.
1343 // So, take the first unexplored path on the way up to 'dom'.
1344 for (int j = nlist.size() - 1; j >= 0; j--) {
1345 intptr_t ni = (intptr_t)nlist.at(j);
1346 Node* visited = (Node*)(ni & ~1);
1347 bool visited_twice_already = ((ni & 1) != 0);
1348 if (visited == sub) {
1349 if (visited_twice_already) {
1350 // Visited 2 paths, but still stuck in loop body. Give up.
1351 return DomResult::NotDominate;
1352 }
1353 // The Region node was visited before only once.
1354 // (We will repush with the low bit set, below.)
1355 nlist.remove(j);
1356 // We will find a new edge and re-insert.
1357 region_was_visited_before = true;
1358 break;
1359 }
1360 }
1361
1362 // Find an incoming edge which has not been seen yet; walk through it.
1363 assert(up == sub, "");
1364 uint skip = region_was_visited_before ? 1 : 0;
1365 for (uint i = 1; i < sub->req(); i++) {
1366 Node* in = sub->in(i);
1367 if (in != nullptr && !in->is_top() && in != sub) {
1368 if (skip == 0) {
1369 up = in;
1370 break;
1371 }
1372 --skip; // skip this nontrivial input
1373 }
1374 }
1375
1376 // Set 0 bit to indicate that both paths were taken.
1377 nlist.push((Node*)((intptr_t)sub + (region_was_visited_before ? 1 : 0)));
1378 }
1379
1380 if (up == sub) {
1381 break; // some kind of tight cycle
1382 }
1383 if (up == orig_sub && met_dom) {
1384 // returned back after visiting 'dom'
1385 break; // some kind of cycle
1386 }
1387 if (--iterations_without_region_limit < 0) {
1388 break; // dead cycle
1389 }
1390 sub = up;
1391 }
1392
1393 // Did not meet Root or Start node in pred. chain.
1394 return DomResult::NotDominate;
1395 }
1396
1397 //------------------------------remove_dead_region-----------------------------
1398 // This control node is dead. Follow the subgraph below it making everything
1399 // using it dead as well. This will happen normally via the usual IterGVN
1400 // worklist but this call is more efficient. Do not update use-def info
1401 // inside the dead region, just at the borders.
1402 static void kill_dead_code( Node *dead, PhaseIterGVN *igvn ) {
1403 // Con's are a popular node to re-hit in the hash table again.
1404 if( dead->is_Con() ) return;
1405
1406 ResourceMark rm;
1407 Node_List nstack;
1408 VectorSet dead_set; // notify uses only once
1409
1410 Node *top = igvn->C->top();
1411 nstack.push(dead);
1412 bool has_irreducible_loop = igvn->C->has_irreducible_loop();
1413
1414 while (nstack.size() > 0) {
1415 dead = nstack.pop();
1416 if (!dead_set.test_set(dead->_idx)) {
1417 // If dead has any live uses, those are now still attached. Notify them before we lose them.
1418 igvn->add_users_to_worklist(dead);
1419 }
1420 if (dead->Opcode() == Op_SafePoint) {
1421 dead->as_SafePoint()->disconnect_from_root(igvn);
1422 }
1423 if (dead->outcnt() > 0) {
1424 // Keep dead node on stack until all uses are processed.
1425 nstack.push(dead);
1426 // For all Users of the Dead... ;-)
1427 for (DUIterator_Last kmin, k = dead->last_outs(kmin); k >= kmin; ) {
1428 Node* use = dead->last_out(k);
1429 igvn->hash_delete(use); // Yank from hash table prior to mod
1430 if (use->in(0) == dead) { // Found another dead node
1431 assert (!use->is_Con(), "Control for Con node should be Root node.");
1432 use->set_req(0, top); // Cut dead edge to prevent processing
1433 nstack.push(use); // the dead node again.
1434 } else if (!has_irreducible_loop && // Backedge could be alive in irreducible loop
1435 use->is_Loop() && !use->is_Root() && // Don't kill Root (RootNode extends LoopNode)
1436 use->in(LoopNode::EntryControl) == dead) { // Dead loop if its entry is dead
1437 use->set_req(LoopNode::EntryControl, top); // Cut dead edge to prevent processing
1438 use->set_req(0, top); // Cut self edge
1439 nstack.push(use);
1440 } else { // Else found a not-dead user
1441 // Dead if all inputs are top or null
1442 bool dead_use = !use->is_Root(); // Keep empty graph alive
1443 for (uint j = 1; j < use->req(); j++) {
1444 Node* in = use->in(j);
1445 if (in == dead) { // Turn all dead inputs into TOP
1446 use->set_req(j, top);
1447 } else if (in != nullptr && !in->is_top()) {
1448 dead_use = false;
1449 }
1450 }
1451 if (dead_use) {
1452 if (use->is_Region()) {
1453 use->set_req(0, top); // Cut self edge
1454 }
1455 nstack.push(use);
1456 } else {
1457 igvn->_worklist.push(use);
1458 }
1459 }
1460 // Refresh the iterator, since any number of kills might have happened.
1461 k = dead->last_outs(kmin);
1462 }
1463 } else { // (dead->outcnt() == 0)
1464 // Done with outputs.
1465 igvn->hash_delete(dead);
1466 igvn->_worklist.remove(dead);
1467 igvn->set_type(dead, Type::TOP);
1468 // Kill all inputs to the dead guy
1469 for (uint i=0; i < dead->req(); i++) {
1470 Node *n = dead->in(i); // Get input to dead guy
1471 if (n != nullptr && !n->is_top()) { // Input is valid?
1472 dead->set_req(i, top); // Smash input away
1473 if (n->outcnt() == 0) { // Input also goes dead?
1474 if (!n->is_Con())
1475 nstack.push(n); // Clear it out as well
1476 } else if (n->outcnt() == 1 &&
1477 n->has_special_unique_user()) {
1478 igvn->add_users_to_worklist( n );
1479 } else if (n->outcnt() <= 2 && n->is_Store()) {
1480 // Push store's uses on worklist to enable folding optimization for
1481 // store/store and store/load to the same address.
1482 // The restriction (outcnt() <= 2) is the same as in set_req_X()
1483 // and remove_globally_dead_node().
1484 igvn->add_users_to_worklist( n );
1485 } else if (dead->is_data_proj_of_pure_function(n)) {
1486 igvn->_worklist.push(n);
1487 } else {
1488 BarrierSet::barrier_set()->barrier_set_c2()->enqueue_useful_gc_barrier(igvn, n);
1489 }
1490 }
1491 }
1492 igvn->C->remove_useless_node(dead);
1493 } // (dead->outcnt() == 0)
1494 } // while (nstack.size() > 0) for outputs
1495 return;
1496 }
1497
1498 //------------------------------remove_dead_region-----------------------------
1499 bool Node::remove_dead_region(PhaseGVN *phase, bool can_reshape) {
1500 Node *n = in(0);
1501 if( !n ) return false;
1502 // Lost control into this guy? I.e., it became unreachable?
1503 // Aggressively kill all unreachable code.
1504 if (can_reshape && n->is_top()) {
1505 kill_dead_code(this, phase->is_IterGVN());
1506 return false; // Node is dead.
1507 }
1508
1509 if( n->is_Region() && n->as_Region()->is_copy() ) {
1510 Node *m = n->nonnull_req();
1511 set_req(0, m);
1512 return true;
1513 }
1514 return false;
1515 }
1516
1517 //------------------------------hash-------------------------------------------
1518 // Hash function over Nodes.
1519 uint Node::hash() const {
1520 uint sum = 0;
1521 for( uint i=0; i<_cnt; i++ ) // Add in all inputs
1522 sum = (sum<<1)-(uintptr_t)in(i); // Ignore embedded nulls
1523 return (sum>>2) + _cnt + Opcode();
1524 }
1525
1526 //------------------------------cmp--------------------------------------------
1527 // Compare special parts of simple Nodes
1528 bool Node::cmp( const Node &n ) const {
1529 return true; // Must be same
1530 }
1531
1532 //------------------------------rematerialize-----------------------------------
1533 // Should we clone rather than spill this instruction?
1534 bool Node::rematerialize() const {
1535 if ( is_Mach() )
1536 return this->as_Mach()->rematerialize();
1537 else
1538 return (_flags & Flag_rematerialize) != 0;
1539 }
1540
1541 //------------------------------needs_anti_dependence_check---------------------
1542 // Nodes which use memory without consuming it, hence need antidependences.
1543 bool Node::needs_anti_dependence_check() const {
1544 if (req() < 2 || (_flags & Flag_needs_anti_dependence_check) == 0) {
1545 return false;
1546 }
1547 return in(1)->bottom_type()->has_memory();
1548 }
1549
1550 // Get an integer constant from a ConNode (or CastIINode).
1551 // Return a default value if there is no apparent constant here.
1552 const TypeInt* Node::find_int_type() const {
1553 if (this->is_Type()) {
1554 return this->as_Type()->type()->isa_int();
1555 } else if (this->is_Con()) {
1556 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1557 return this->bottom_type()->isa_int();
1558 }
1559 return nullptr;
1560 }
1561
1562 const TypeInteger* Node::find_integer_type(BasicType bt) const {
1563 if (this->is_Type()) {
1564 return this->as_Type()->type()->isa_integer(bt);
1565 } else if (this->is_Con()) {
1566 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1567 return this->bottom_type()->isa_integer(bt);
1568 }
1569 return nullptr;
1570 }
1571
1572 // Get a pointer constant from a ConstNode.
1573 // Returns the constant if it is a pointer ConstNode
1574 intptr_t Node::get_ptr() const {
1575 assert( Opcode() == Op_ConP, "" );
1576 return ((ConPNode*)this)->type()->is_ptr()->get_con();
1577 }
1578
1579 // Get a narrow oop constant from a ConNNode.
1580 intptr_t Node::get_narrowcon() const {
1581 assert( Opcode() == Op_ConN, "" );
1582 return ((ConNNode*)this)->type()->is_narrowoop()->get_con();
1583 }
1584
1585 // Get a long constant from a ConNode.
1586 // Return a default value if there is no apparent constant here.
1587 const TypeLong* Node::find_long_type() const {
1588 if (this->is_Type()) {
1589 return this->as_Type()->type()->isa_long();
1590 } else if (this->is_Con()) {
1591 assert(is_Mach(), "should be ConNode(TypeNode) or else a MachNode");
1592 return this->bottom_type()->isa_long();
1593 }
1594 return nullptr;
1595 }
1596
1597
1598 /**
1599 * Return a ptr type for nodes which should have it.
1600 */
1601 const TypePtr* Node::get_ptr_type() const {
1602 const TypePtr* tp = this->bottom_type()->make_ptr();
1603 #ifdef ASSERT
1604 if (tp == nullptr) {
1605 this->dump(1);
1606 assert((tp != nullptr), "unexpected node type");
1607 }
1608 #endif
1609 return tp;
1610 }
1611
1612 // Get a double constant from a ConstNode.
1613 // Returns the constant if it is a double ConstNode
1614 jdouble Node::getd() const {
1615 assert( Opcode() == Op_ConD, "" );
1616 return ((ConDNode*)this)->type()->is_double_constant()->getd();
1617 }
1618
1619 // Get a float constant from a ConstNode.
1620 // Returns the constant if it is a float ConstNode
1621 jfloat Node::getf() const {
1622 assert( Opcode() == Op_ConF, "" );
1623 return ((ConFNode*)this)->type()->is_float_constant()->getf();
1624 }
1625
1626 // Get a half float constant from a ConstNode.
1627 // Returns the constant if it is a float ConstNode
1628 jshort Node::geth() const {
1629 assert( Opcode() == Op_ConH, "" );
1630 return ((ConHNode*)this)->type()->is_half_float_constant()->geth();
1631 }
1632
1633 #ifndef PRODUCT
1634
1635 // Call this from debugger:
1636 Node* old_root() {
1637 Matcher* matcher = Compile::current()->matcher();
1638 if (matcher != nullptr) {
1639 Node* new_root = Compile::current()->root();
1640 Node* old_root = matcher->find_old_node(new_root);
1641 if (old_root != nullptr) {
1642 return old_root;
1643 }
1644 }
1645 tty->print("old_root: not found.\n");
1646 return nullptr;
1647 }
1648
1649 // BFS traverse all reachable nodes from start, call callback on them
1650 template <typename Callback>
1651 void visit_nodes(Node* start, Callback callback, bool traverse_output, bool only_ctrl) {
1652 Unique_Mixed_Node_List worklist;
1653 worklist.add(start);
1654 for (uint i = 0; i < worklist.size(); i++) {
1655 Node* n = worklist[i];
1656 callback(n);
1657 for (uint i = 0; i < n->len(); i++) {
1658 if (!only_ctrl || n->is_Region() || (n->Opcode() == Op_Root) || (i == TypeFunc::Control)) {
1659 // If only_ctrl is set: Add regions, the root node, or control inputs only
1660 worklist.add(n->in(i));
1661 }
1662 }
1663 if (traverse_output && !only_ctrl) {
1664 for (uint i = 0; i < n->outcnt(); i++) {
1665 worklist.add(n->raw_out(i));
1666 }
1667 }
1668 }
1669 }
1670
1671 // BFS traverse from start, return node with idx
1672 static Node* find_node_by_idx(Node* start, uint idx, bool traverse_output, bool only_ctrl) {
1673 ResourceMark rm;
1674 Node* result = nullptr;
1675 auto callback = [&] (Node* n) {
1676 if (n->_idx == idx) {
1677 if (result != nullptr) {
1678 tty->print("find_node_by_idx: " INTPTR_FORMAT " and " INTPTR_FORMAT " both have idx==%d\n",
1679 (uintptr_t)result, (uintptr_t)n, idx);
1680 }
1681 result = n;
1682 }
1683 };
1684 visit_nodes(start, callback, traverse_output, only_ctrl);
1685 return result;
1686 }
1687
1688 static int node_idx_cmp(const Node** n1, const Node** n2) {
1689 return (*n1)->_idx - (*n2)->_idx;
1690 }
1691
1692 static void find_nodes_by_name(Node* start, const char* name) {
1693 ResourceMark rm;
1694 GrowableArray<const Node*> ns;
1695 auto callback = [&] (const Node* n) {
1696 if (StringUtils::is_star_match(name, n->Name())) {
1697 ns.push(n);
1698 }
1699 };
1700 visit_nodes(start, callback, true, false);
1701 ns.sort(node_idx_cmp);
1702 for (int i = 0; i < ns.length(); i++) {
1703 ns.at(i)->dump();
1704 }
1705 }
1706
1707 static void find_nodes_by_dump(Node* start, const char* pattern) {
1708 ResourceMark rm;
1709 GrowableArray<const Node*> ns;
1710 auto callback = [&] (const Node* n) {
1711 stringStream stream;
1712 n->dump("", false, &stream);
1713 if (StringUtils::is_star_match(pattern, stream.base())) {
1714 ns.push(n);
1715 }
1716 };
1717 visit_nodes(start, callback, true, false);
1718 ns.sort(node_idx_cmp);
1719 for (int i = 0; i < ns.length(); i++) {
1720 ns.at(i)->dump();
1721 }
1722 }
1723
1724 // call from debugger: find node with name pattern in new/current graph
1725 // name can contain "*" in match pattern to match any characters
1726 // the matching is case insensitive
1727 void find_nodes_by_name(const char* name) {
1728 Node* root = Compile::current()->root();
1729 find_nodes_by_name(root, name);
1730 }
1731
1732 // call from debugger: find node with name pattern in old graph
1733 // name can contain "*" in match pattern to match any characters
1734 // the matching is case insensitive
1735 void find_old_nodes_by_name(const char* name) {
1736 Node* root = old_root();
1737 find_nodes_by_name(root, name);
1738 }
1739
1740 // call from debugger: find node with dump pattern in new/current graph
1741 // can contain "*" in match pattern to match any characters
1742 // the matching is case insensitive
1743 void find_nodes_by_dump(const char* pattern) {
1744 Node* root = Compile::current()->root();
1745 find_nodes_by_dump(root, pattern);
1746 }
1747
1748 // call from debugger: find node with name pattern in old graph
1749 // can contain "*" in match pattern to match any characters
1750 // the matching is case insensitive
1751 void find_old_nodes_by_dump(const char* pattern) {
1752 Node* root = old_root();
1753 find_nodes_by_dump(root, pattern);
1754 }
1755
1756 // Call this from debugger, search in same graph as n:
1757 Node* find_node(Node* n, const int idx) {
1758 return n->find(idx);
1759 }
1760
1761 // Call this from debugger, search in new nodes:
1762 Node* find_node(const int idx) {
1763 return Compile::current()->root()->find(idx);
1764 }
1765
1766 // Call this from debugger, search in old nodes:
1767 Node* find_old_node(const int idx) {
1768 Node* root = old_root();
1769 return (root == nullptr) ? nullptr : root->find(idx);
1770 }
1771
1772 // Call this from debugger, search in same graph as n:
1773 Node* find_ctrl(Node* n, const int idx) {
1774 return n->find_ctrl(idx);
1775 }
1776
1777 // Call this from debugger, search in new nodes:
1778 Node* find_ctrl(const int idx) {
1779 return Compile::current()->root()->find_ctrl(idx);
1780 }
1781
1782 // Call this from debugger, search in old nodes:
1783 Node* find_old_ctrl(const int idx) {
1784 Node* root = old_root();
1785 return (root == nullptr) ? nullptr : root->find_ctrl(idx);
1786 }
1787
1788 //------------------------------find_ctrl--------------------------------------
1789 // Find an ancestor to this node in the control history with given _idx
1790 Node* Node::find_ctrl(int idx) {
1791 return find(idx, true);
1792 }
1793
1794 //------------------------------find-------------------------------------------
1795 // Tries to find the node with the index |idx| starting from this node. If idx is negative,
1796 // the search also includes forward (out) edges. Returns null if not found.
1797 // If only_ctrl is set, the search will only be done on control nodes. Returns null if
1798 // not found or if the node to be found is not a control node (search will not find it).
1799 Node* Node::find(const int idx, bool only_ctrl) {
1800 ResourceMark rm;
1801 return find_node_by_idx(this, abs(idx), (idx < 0), only_ctrl);
1802 }
1803
1804 class PrintBFS {
1805 public:
1806 PrintBFS(const Node* start, const int max_distance, const Node* target, const char* options, outputStream* st, const frame* fr)
1807 : _start(start), _max_distance(max_distance), _target(target), _options(options), _output(st), _frame(fr),
1808 _dcc(this), _info_uid(cmpkey, hashkey) {}
1809
1810 void run();
1811 private:
1812 // pipeline steps
1813 bool configure();
1814 void collect();
1815 void select();
1816 void select_all();
1817 void select_all_paths();
1818 void select_shortest_path();
1819 void sort();
1820 void print();
1821
1822 // inputs
1823 const Node* _start;
1824 const int _max_distance;
1825 const Node* _target;
1826 const char* _options;
1827 outputStream* _output;
1828 const frame* _frame;
1829
1830 // options
1831 bool _traverse_inputs = false;
1832 bool _traverse_outputs = false;
1833 struct Filter {
1834 bool _control = false;
1835 bool _memory = false;
1836 bool _data = false;
1837 bool _mixed = false;
1838 bool _other = false;
1839 bool is_empty() const {
1840 return !(_control || _memory || _data || _mixed || _other);
1841 }
1842 void set_all() {
1843 _control = true;
1844 _memory = true;
1845 _data = true;
1846 _mixed = true;
1847 _other = true;
1848 }
1849 // Check if the filter accepts the node. Go by the type categories, but also all CFG nodes
1850 // are considered to have control.
1851 bool accepts(const Node* n) {
1852 const Type* t = n->bottom_type();
1853 return ( _data && t->has_category(Type::Category::Data) ) ||
1854 ( _memory && t->has_category(Type::Category::Memory) ) ||
1855 ( _mixed && t->has_category(Type::Category::Mixed) ) ||
1856 ( _control && (t->has_category(Type::Category::Control) || n->is_CFG()) ) ||
1857 ( _other && t->has_category(Type::Category::Other) );
1858 }
1859 };
1860 Filter _filter_visit;
1861 Filter _filter_boundary;
1862 bool _sort_idx = false;
1863 bool _all_paths = false;
1864 bool _use_color = false;
1865 bool _print_blocks = false;
1866 bool _print_old = false;
1867 bool _dump_only = false;
1868 bool _print_igv = false;
1869
1870 void print_options_help(bool print_examples);
1871 bool parse_options();
1872
1873 public:
1874 class DumpConfigColored : public Node::DumpConfig {
1875 public:
1876 DumpConfigColored(PrintBFS* bfs) : _bfs(bfs) {};
1877 virtual void pre_dump(outputStream* st, const Node* n);
1878 virtual void post_dump(outputStream* st);
1879 private:
1880 PrintBFS* _bfs;
1881 };
1882 private:
1883 DumpConfigColored _dcc;
1884
1885 // node info
1886 static Node* old_node(const Node* n); // mach node -> prior IR node
1887 void print_node_idx(const Node* n);
1888 void print_block_id(const Block* b);
1889 void print_node_block(const Node* n); // _pre_order, head idx, _idom, _dom_depth
1890
1891 // traversal data structures
1892 GrowableArray<const Node*> _worklist; // BFS queue
1893 void maybe_traverse(const Node* src, const Node* dst);
1894
1895 // node info annotation
1896 class Info {
1897 public:
1898 Info() : Info(nullptr, 0) {};
1899 Info(const Node* node, int distance)
1900 : _node(node), _distance_from_start(distance) {};
1901 const Node* node() const { return _node; };
1902 int distance() const { return _distance_from_start; };
1903 int distance_from_target() const { return _distance_from_target; }
1904 void set_distance_from_target(int d) { _distance_from_target = d; }
1905 GrowableArray<const Node*> edge_bwd; // pointing toward _start
1906 bool is_marked() const { return _mark; } // marked to keep during select
1907 void set_mark() { _mark = true; }
1908 private:
1909 const Node* _node;
1910 int _distance_from_start; // distance from _start
1911 int _distance_from_target = 0; // distance from _target if _all_paths
1912 bool _mark = false;
1913 };
1914 Dict _info_uid; // Node -> uid
1915 GrowableArray<Info> _info; // uid -> info
1916
1917 Info* find_info(const Node* n) {
1918 size_t uid = (size_t)_info_uid[n];
1919 if (uid == 0) {
1920 return nullptr;
1921 }
1922 return &_info.at((int)uid);
1923 }
1924
1925 void make_info(const Node* node, const int distance) {
1926 assert(find_info(node) == nullptr, "node does not yet have info");
1927 size_t uid = _info.length() + 1;
1928 _info_uid.Insert((void*)node, (void*)uid);
1929 _info.at_put_grow((int)uid, Info(node, distance));
1930 assert(find_info(node)->node() == node, "stored correct node");
1931 };
1932
1933 // filled by sort, printed by print
1934 GrowableArray<const Node*> _print_list;
1935
1936 // print header + node table
1937 void print_header() const;
1938 void print_node(const Node* n);
1939 };
1940
1941 void PrintBFS::run() {
1942 if (!configure()) {
1943 return;
1944 }
1945 collect();
1946 select();
1947 sort();
1948 print();
1949 }
1950
1951 // set up configuration for BFS and print
1952 bool PrintBFS::configure() {
1953 if (_max_distance < 0) {
1954 _output->print_cr("dump_bfs: max_distance must be non-negative!");
1955 return false;
1956 }
1957 return parse_options();
1958 }
1959
1960 // BFS traverse according to configuration, fill worklist and info
1961 void PrintBFS::collect() {
1962 maybe_traverse(_start, _start);
1963 int pos = 0;
1964 while (pos < _worklist.length()) {
1965 const Node* n = _worklist.at(pos++); // next node to traverse
1966 Info* info = find_info(n);
1967 if (!_filter_visit.accepts(n) && n != _start) {
1968 continue; // we hit boundary, do not traverse further
1969 }
1970 if (n != _start && n->is_Root()) {
1971 continue; // traversing through root node would lead to unrelated nodes
1972 }
1973 if (_traverse_inputs && _max_distance > info->distance()) {
1974 for (uint i = 0; i < n->req(); i++) {
1975 maybe_traverse(n, n->in(i));
1976 }
1977 }
1978 if (_traverse_outputs && _max_distance > info->distance()) {
1979 for (uint i = 0; i < n->outcnt(); i++) {
1980 maybe_traverse(n, n->raw_out(i));
1981 }
1982 }
1983 }
1984 }
1985
1986 // go through work list, mark those that we want to print
1987 void PrintBFS::select() {
1988 if (_target == nullptr ) {
1989 select_all();
1990 } else {
1991 if (find_info(_target) == nullptr) {
1992 _output->print_cr("Could not find target in BFS.");
1993 return;
1994 }
1995 if (_all_paths) {
1996 select_all_paths();
1997 } else {
1998 select_shortest_path();
1999 }
2000 }
2001 }
2002
2003 // take all nodes from BFS
2004 void PrintBFS::select_all() {
2005 for (int i = 0; i < _worklist.length(); i++) {
2006 const Node* n = _worklist.at(i);
2007 Info* info = find_info(n);
2008 info->set_mark();
2009 }
2010 }
2011
2012 // traverse backward from target, along edges found in BFS
2013 void PrintBFS::select_all_paths() {
2014 int pos = 0;
2015 GrowableArray<const Node*> backtrace;
2016 // start from target
2017 backtrace.push(_target);
2018 find_info(_target)->set_mark();
2019 // traverse backward
2020 while (pos < backtrace.length()) {
2021 const Node* n = backtrace.at(pos++);
2022 Info* info = find_info(n);
2023 for (int i = 0; i < info->edge_bwd.length(); i++) {
2024 // all backward edges
2025 const Node* back = info->edge_bwd.at(i);
2026 Info* back_info = find_info(back);
2027 if (!back_info->is_marked()) {
2028 // not yet found this on way back.
2029 back_info->set_distance_from_target(info->distance_from_target() + 1);
2030 if (back_info->distance_from_target() + back_info->distance() <= _max_distance) {
2031 // total distance is small enough
2032 back_info->set_mark();
2033 backtrace.push(back);
2034 }
2035 }
2036 }
2037 }
2038 }
2039
2040 void PrintBFS::select_shortest_path() {
2041 const Node* current = _target;
2042 while (true) {
2043 Info* info = find_info(current);
2044 info->set_mark();
2045 if (current == _start) {
2046 break;
2047 }
2048 // first edge -> leads us one step closer to _start
2049 current = info->edge_bwd.at(0);
2050 }
2051 }
2052
2053 // go through worklist in desired order, put the marked ones in print list
2054 void PrintBFS::sort() {
2055 if (_traverse_inputs && !_traverse_outputs) {
2056 // reverse order
2057 for (int i = _worklist.length() - 1; i >= 0; i--) {
2058 const Node* n = _worklist.at(i);
2059 Info* info = find_info(n);
2060 if (info->is_marked()) {
2061 _print_list.push(n);
2062 }
2063 }
2064 } else {
2065 // same order as worklist
2066 for (int i = 0; i < _worklist.length(); i++) {
2067 const Node* n = _worklist.at(i);
2068 Info* info = find_info(n);
2069 if (info->is_marked()) {
2070 _print_list.push(n);
2071 }
2072 }
2073 }
2074 if (_sort_idx) {
2075 _print_list.sort(node_idx_cmp);
2076 }
2077 }
2078
2079 // go through printlist and print
2080 void PrintBFS::print() {
2081 if (_print_list.length() > 0 ) {
2082 print_header();
2083 for (int i = 0; i < _print_list.length(); i++) {
2084 const Node* n = _print_list.at(i);
2085 print_node(n);
2086 }
2087 if (_print_igv) {
2088 Compile* C = Compile::current();
2089 C->init_igv();
2090 C->igv_print_graph_to_network(nullptr, _print_list, _frame);
2091 }
2092 } else {
2093 _output->print_cr("No nodes to print.");
2094 }
2095 }
2096
2097 void PrintBFS::print_options_help(bool print_examples) {
2098 _output->print_cr("Usage: node->dump_bfs(int max_distance, Node* target, char* options)");
2099 _output->print_cr("");
2100 _output->print_cr("Use cases:");
2101 _output->print_cr(" BFS traversal: no target required");
2102 _output->print_cr(" shortest path: set target");
2103 _output->print_cr(" all paths: set target and put 'A' in options");
2104 _output->print_cr(" detect loop: subcase of all paths, have start==target");
2105 _output->print_cr("");
2106 _output->print_cr("Arguments:");
2107 _output->print_cr(" this/start: staring point of BFS");
2108 _output->print_cr(" target:");
2109 _output->print_cr(" if null: simple BFS");
2110 _output->print_cr(" else: shortest path or all paths between this/start and target");
2111 _output->print_cr(" options:");
2112 _output->print_cr(" if null: same as \"cdmox@B\"");
2113 _output->print_cr(" else: use combination of following characters");
2114 _output->print_cr(" h: display this help info");
2115 _output->print_cr(" H: display this help info, with examples");
2116 _output->print_cr(" +: traverse in-edges (on if neither + nor -)");
2117 _output->print_cr(" -: traverse out-edges");
2118 _output->print_cr(" c: visit control nodes");
2119 _output->print_cr(" d: visit data nodes");
2120 _output->print_cr(" m: visit memory nodes");
2121 _output->print_cr(" o: visit other nodes");
2122 _output->print_cr(" x: visit mixed nodes");
2123 _output->print_cr(" C: boundary control nodes");
2124 _output->print_cr(" D: boundary data nodes");
2125 _output->print_cr(" M: boundary memory nodes");
2126 _output->print_cr(" O: boundary other nodes");
2127 _output->print_cr(" X: boundary mixed nodes");
2128 _output->print_cr(" #: display node category in color (not supported in all terminals)");
2129 _output->print_cr(" S: sort displayed nodes by node idx");
2130 _output->print_cr(" A: all paths (not just shortest path to target)");
2131 _output->print_cr(" @: print old nodes - before matching (if available)");
2132 _output->print_cr(" B: print scheduling blocks (if available)");
2133 _output->print_cr(" $: dump only, no header, no other columns");
2134 _output->print_cr(" !: show nodes on IGV (sent over network stream)");
2135 _output->print_cr(" (use preferably with dump_bfs(int, Node*, char*, void*, void*, void*)");
2136 _output->print_cr(" to produce a C2 stack trace along with the graph dump, see examples below)");
2137 _output->print_cr("");
2138 _output->print_cr("recursively follow edges to nodes with permitted visit types,");
2139 _output->print_cr("on the boundary additionally display nodes allowed in boundary types");
2140 _output->print_cr("Note: the categories can be overlapping. For example a mixed node");
2141 _output->print_cr(" can contain control and memory output. Some from the other");
2142 _output->print_cr(" category are also control (Halt, Return, etc).");
2143 _output->print_cr("");
2144 _output->print_cr("output columns:");
2145 _output->print_cr(" dist: BFS distance to this/start");
2146 _output->print_cr(" apd: all paths distance (d_outputart + d_target)");
2147 _output->print_cr(" block: block identifier, based on _pre_order");
2148 _output->print_cr(" head: first node in block");
2149 _output->print_cr(" idom: head node of idom block");
2150 _output->print_cr(" depth: depth of block (_dom_depth)");
2151 _output->print_cr(" old: old IR node - before matching");
2152 _output->print_cr(" dump: node->dump()");
2153 _output->print_cr("");
2154 _output->print_cr("Note: if none of the \"cmdxo\" characters are in the options string");
2155 _output->print_cr(" then we set all of them.");
2156 _output->print_cr(" This allows for short strings like \"#\" for colored input traversal");
2157 _output->print_cr(" or \"-#\" for colored output traversal.");
2158 if (print_examples) {
2159 _output->print_cr("");
2160 _output->print_cr("Examples:");
2161 _output->print_cr(" if->dump_bfs(10, 0, \"+cxo\")");
2162 _output->print_cr(" starting at some if node, traverse inputs recursively");
2163 _output->print_cr(" only along control (mixed and other can also be control)");
2164 _output->print_cr(" phi->dump_bfs(5, 0, \"-dxo\")");
2165 _output->print_cr(" starting at phi node, traverse outputs recursively");
2166 _output->print_cr(" only along data (mixed and other can also have data flow)");
2167 _output->print_cr(" find_node(385)->dump_bfs(3, 0, \"cdmox+#@B\")");
2168 _output->print_cr(" find inputs of node 385, up to 3 nodes up (+)");
2169 _output->print_cr(" traverse all nodes (cdmox), use colors (#)");
2170 _output->print_cr(" display old nodes and blocks, if they exist");
2171 _output->print_cr(" useful call to start with");
2172 _output->print_cr(" find_node(102)->dump_bfs(10, 0, \"dCDMOX-\")");
2173 _output->print_cr(" find non-data dependencies of a data node");
2174 _output->print_cr(" follow data node outputs until we find another category");
2175 _output->print_cr(" node as the boundary");
2176 _output->print_cr(" x->dump_bfs(10, y, 0)");
2177 _output->print_cr(" find shortest path from x to y, along any edge or node");
2178 _output->print_cr(" will not find a path if it is longer than 10");
2179 _output->print_cr(" useful to find how x and y are related");
2180 _output->print_cr(" find_node(741)->dump_bfs(20, find_node(746), \"c+\")");
2181 _output->print_cr(" find shortest control path between two nodes");
2182 _output->print_cr(" find_node(741)->dump_bfs(8, find_node(746), \"cdmox+A\")");
2183 _output->print_cr(" find all paths (A) between two nodes of length at most 8");
2184 _output->print_cr(" find_node(741)->dump_bfs(7, find_node(741), \"c+A\")");
2185 _output->print_cr(" find all control loops for this node");
2186 _output->print_cr(" find_node(741)->dump_bfs(7, find_node(741), \"c+A!\", $sp, $fp, $pc)");
2187 _output->print_cr(" same as above, but printing the resulting subgraph");
2188 _output->print_cr(" along with a C2 stack trace on IGV");
2189 }
2190 }
2191
2192 bool PrintBFS::parse_options() {
2193 if (_options == nullptr) {
2194 _options = "cdmox@B"; // default options
2195 }
2196 size_t len = strlen(_options);
2197 for (size_t i = 0; i < len; i++) {
2198 switch (_options[i]) {
2199 case '+':
2200 _traverse_inputs = true;
2201 break;
2202 case '-':
2203 _traverse_outputs = true;
2204 break;
2205 case 'c':
2206 _filter_visit._control = true;
2207 break;
2208 case 'm':
2209 _filter_visit._memory = true;
2210 break;
2211 case 'd':
2212 _filter_visit._data = true;
2213 break;
2214 case 'x':
2215 _filter_visit._mixed = true;
2216 break;
2217 case 'o':
2218 _filter_visit._other = true;
2219 break;
2220 case 'C':
2221 _filter_boundary._control = true;
2222 break;
2223 case 'M':
2224 _filter_boundary._memory = true;
2225 break;
2226 case 'D':
2227 _filter_boundary._data = true;
2228 break;
2229 case 'X':
2230 _filter_boundary._mixed = true;
2231 break;
2232 case 'O':
2233 _filter_boundary._other = true;
2234 break;
2235 case 'S':
2236 _sort_idx = true;
2237 break;
2238 case 'A':
2239 _all_paths = true;
2240 break;
2241 case '#':
2242 _use_color = true;
2243 break;
2244 case 'B':
2245 _print_blocks = true;
2246 break;
2247 case '@':
2248 _print_old = true;
2249 break;
2250 case '$':
2251 _dump_only = true;
2252 break;
2253 case '!':
2254 _print_igv = true;
2255 break;
2256 case 'h':
2257 print_options_help(false);
2258 return false;
2259 case 'H':
2260 print_options_help(true);
2261 return false;
2262 default:
2263 _output->print_cr("dump_bfs: Unrecognized option \'%c\'", _options[i]);
2264 _output->print_cr("for help, run: find_node(0)->dump_bfs(0,0,\"H\")");
2265 return false;
2266 }
2267 }
2268 if (!_traverse_inputs && !_traverse_outputs) {
2269 _traverse_inputs = true;
2270 }
2271 if (_filter_visit.is_empty()) {
2272 _filter_visit.set_all();
2273 }
2274 Compile* C = Compile::current();
2275 _print_old &= (C->matcher() != nullptr); // only show old if there are new
2276 _print_blocks &= (C->cfg() != nullptr); // only show blocks if available
2277 return true;
2278 }
2279
2280 void PrintBFS::DumpConfigColored::pre_dump(outputStream* st, const Node* n) {
2281 if (!_bfs->_use_color) {
2282 return;
2283 }
2284 Info* info = _bfs->find_info(n);
2285 if (info == nullptr || !info->is_marked()) {
2286 return;
2287 }
2288
2289 const Type* t = n->bottom_type();
2290 switch (t->category()) {
2291 case Type::Category::Data:
2292 st->print("\u001b[34m");
2293 break;
2294 case Type::Category::Memory:
2295 st->print("\u001b[32m");
2296 break;
2297 case Type::Category::Mixed:
2298 st->print("\u001b[35m");
2299 break;
2300 case Type::Category::Control:
2301 st->print("\u001b[31m");
2302 break;
2303 case Type::Category::Other:
2304 st->print("\u001b[33m");
2305 break;
2306 case Type::Category::Undef:
2307 n->dump();
2308 assert(false, "category undef ??");
2309 break;
2310 default:
2311 n->dump();
2312 assert(false, "not covered");
2313 break;
2314 }
2315 }
2316
2317 void PrintBFS::DumpConfigColored::post_dump(outputStream* st) {
2318 if (!_bfs->_use_color) {
2319 return;
2320 }
2321 st->print("\u001b[0m"); // white
2322 }
2323
2324 Node* PrintBFS::old_node(const Node* n) {
2325 Compile* C = Compile::current();
2326 if (C->matcher() == nullptr || !C->node_arena()->contains(n)) {
2327 return (Node*)nullptr;
2328 } else {
2329 return C->matcher()->find_old_node(n);
2330 }
2331 }
2332
2333 void PrintBFS::print_node_idx(const Node* n) {
2334 Compile* C = Compile::current();
2335 char buf[30];
2336 if (n == nullptr) {
2337 os::snprintf_checked(buf, sizeof(buf), "_"); // null
2338 } else if (C->node_arena()->contains(n)) {
2339 os::snprintf_checked(buf, sizeof(buf), "%d", n->_idx); // new node
2340 } else {
2341 os::snprintf_checked(buf, sizeof(buf), "o%d", n->_idx); // old node
2342 }
2343 _output->print("%6s", buf);
2344 }
2345
2346 void PrintBFS::print_block_id(const Block* b) {
2347 Compile* C = Compile::current();
2348 char buf[30];
2349 os::snprintf_checked(buf, sizeof(buf), "B%d", b->_pre_order);
2350 _output->print("%7s", buf);
2351 }
2352
2353 void PrintBFS::print_node_block(const Node* n) {
2354 Compile* C = Compile::current();
2355 Block* b = C->node_arena()->contains(n)
2356 ? C->cfg()->get_block_for_node(n)
2357 : nullptr; // guard against old nodes
2358 if (b == nullptr) {
2359 _output->print(" _"); // Block
2360 _output->print(" _"); // head
2361 _output->print(" _"); // idom
2362 _output->print(" _"); // depth
2363 } else {
2364 print_block_id(b);
2365 print_node_idx(b->head());
2366 if (b->_idom) {
2367 print_node_idx(b->_idom->head());
2368 } else {
2369 _output->print(" _"); // idom
2370 }
2371 _output->print("%6d ", b->_dom_depth);
2372 }
2373 }
2374
2375 // filter, and add to worklist, add info, note traversal edges
2376 void PrintBFS::maybe_traverse(const Node* src, const Node* dst) {
2377 if (dst != nullptr &&
2378 (_filter_visit.accepts(dst) ||
2379 _filter_boundary.accepts(dst) ||
2380 dst == _start)) { // correct category or start?
2381 if (find_info(dst) == nullptr) {
2382 // never visited - set up info
2383 _worklist.push(dst);
2384 int d = 0;
2385 if (dst != _start) {
2386 d = find_info(src)->distance() + 1;
2387 }
2388 make_info(dst, d);
2389 }
2390 if (src != dst) {
2391 // traversal edges useful during select
2392 find_info(dst)->edge_bwd.push(src);
2393 }
2394 }
2395 }
2396
2397 void PrintBFS::print_header() const {
2398 if (_dump_only) {
2399 return; // no header in dump only mode
2400 }
2401 _output->print("dist"); // distance
2402 if (_all_paths) {
2403 _output->print(" apd"); // all paths distance
2404 }
2405 if (_print_blocks) {
2406 _output->print(" [block head idom depth]"); // block
2407 }
2408 if (_print_old) {
2409 _output->print(" old"); // old node
2410 }
2411 _output->print(" dump\n"); // node dump
2412 _output->print_cr("---------------------------------------------");
2413 }
2414
2415 void PrintBFS::print_node(const Node* n) {
2416 if (_dump_only) {
2417 n->dump("\n", false, _output, &_dcc);
2418 return;
2419 }
2420 _output->print("%4d", find_info(n)->distance());// distance
2421 if (_all_paths) {
2422 Info* info = find_info(n);
2423 int apd = info->distance() + info->distance_from_target();
2424 _output->print("%4d", apd); // all paths distance
2425 }
2426 if (_print_blocks) {
2427 print_node_block(n); // block
2428 }
2429 if (_print_old) {
2430 print_node_idx(old_node(n)); // old node
2431 }
2432 _output->print(" ");
2433 n->dump("\n", false, _output, &_dcc); // node dump
2434 }
2435
2436 //------------------------------dump_bfs--------------------------------------
2437 // Call this from debugger
2438 // Useful for BFS traversal, shortest path, all path, loop detection, etc
2439 // Designed to be more readable, and provide additional info
2440 // To find all options, run:
2441 // find_node(0)->dump_bfs(0,0,"H")
2442 void Node::dump_bfs(const int max_distance, Node* target, const char* options) const {
2443 dump_bfs(max_distance, target, options, tty);
2444 }
2445
2446 // Used to dump to stream.
2447 void Node::dump_bfs(const int max_distance, Node* target, const char* options, outputStream* st, const frame* fr) const {
2448 PrintBFS bfs(this, max_distance, target, options, st, fr);
2449 bfs.run();
2450 }
2451
2452 // Call this from debugger, with default arguments
2453 void Node::dump_bfs(const int max_distance) const {
2454 dump_bfs(max_distance, nullptr, nullptr);
2455 }
2456
2457 // Call this from debugger, with stack handling register arguments for IGV dumps.
2458 // Example: p find_node(741)->dump_bfs(7, find_node(741), "c+A!", $sp, $fp, $pc).
2459 void Node::dump_bfs(const int max_distance, Node* target, const char* options, void* sp, void* fp, void* pc) const {
2460 frame fr(sp, fp, pc);
2461 dump_bfs(max_distance, target, options, tty, &fr);
2462 }
2463
2464 // -----------------------------dump_idx---------------------------------------
2465 void Node::dump_idx(bool align, outputStream* st, DumpConfig* dc) const {
2466 if (dc != nullptr) {
2467 dc->pre_dump(st, this);
2468 }
2469 Compile* C = Compile::current();
2470 bool is_new = C->node_arena()->contains(this);
2471 if (align) { // print prefix empty spaces$
2472 // +1 for leading digit, +1 for "o"
2473 uint max_width = (C->unique() == 0 ? 0 : static_cast<uint>(log10(static_cast<double>(C->unique())))) + 2;
2474 // +1 for leading digit, maybe +1 for "o"
2475 uint width = (_idx == 0 ? 0 : static_cast<uint>(log10(static_cast<double>(_idx)))) + 1 + (is_new ? 0 : 1);
2476 while (max_width > width) {
2477 st->print(" ");
2478 width++;
2479 }
2480 }
2481 if (!is_new) {
2482 st->print("o");
2483 }
2484 st->print("%d", _idx);
2485 if (dc != nullptr) {
2486 dc->post_dump(st);
2487 }
2488 }
2489
2490 // -----------------------------dump_name--------------------------------------
2491 void Node::dump_name(outputStream* st, DumpConfig* dc) const {
2492 if (dc != nullptr) {
2493 dc->pre_dump(st, this);
2494 }
2495 st->print("%s", Name());
2496 if (dc != nullptr) {
2497 dc->post_dump(st);
2498 }
2499 }
2500
2501 // -----------------------------Name-------------------------------------------
2502 extern const char *NodeClassNames[];
2503 const char *Node::Name() const { return NodeClassNames[Opcode()]; }
2504
2505 static bool is_disconnected(const Node* n) {
2506 for (uint i = 0; i < n->req(); i++) {
2507 if (n->in(i) != nullptr) return false;
2508 }
2509 return true;
2510 }
2511
2512 #ifdef ASSERT
2513 void Node::dump_orig(outputStream *st, bool print_key) const {
2514 Compile* C = Compile::current();
2515 Node* orig = _debug_orig;
2516 if (not_a_node(orig)) orig = nullptr;
2517 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2518 if (orig == nullptr) return;
2519 if (print_key) {
2520 st->print(" !orig=");
2521 }
2522 Node* fast = orig->debug_orig(); // tortoise & hare algorithm to detect loops
2523 if (not_a_node(fast)) fast = nullptr;
2524 while (orig != nullptr) {
2525 bool discon = is_disconnected(orig); // if discon, print [123] else 123
2526 if (discon) st->print("[");
2527 if (!Compile::current()->node_arena()->contains(orig))
2528 st->print("o");
2529 st->print("%d", orig->_idx);
2530 if (discon) st->print("]");
2531 orig = orig->debug_orig();
2532 if (not_a_node(orig)) orig = nullptr;
2533 if (orig != nullptr && !C->node_arena()->contains(orig)) orig = nullptr;
2534 if (orig != nullptr) st->print(",");
2535 if (fast != nullptr) {
2536 // Step fast twice for each single step of orig:
2537 fast = fast->debug_orig();
2538 if (not_a_node(fast)) fast = nullptr;
2539 if (fast != nullptr && fast != orig) {
2540 fast = fast->debug_orig();
2541 if (not_a_node(fast)) fast = nullptr;
2542 }
2543 if (fast == orig) {
2544 st->print("...");
2545 break;
2546 }
2547 }
2548 }
2549 }
2550
2551 void Node::set_debug_orig(Node* orig) {
2552 _debug_orig = orig;
2553 if (BreakAtNode == 0) return;
2554 if (not_a_node(orig)) orig = nullptr;
2555 int trip = 10;
2556 while (orig != nullptr) {
2557 if (orig->debug_idx() == BreakAtNode || (uintx)orig->_idx == BreakAtNode) {
2558 tty->print_cr("BreakAtNode: _idx=%d _debug_idx=" UINT64_FORMAT " orig._idx=%d orig._debug_idx=" UINT64_FORMAT,
2559 this->_idx, this->debug_idx(), orig->_idx, orig->debug_idx());
2560 BREAKPOINT;
2561 }
2562 orig = orig->debug_orig();
2563 if (not_a_node(orig)) orig = nullptr;
2564 if (trip-- <= 0) break;
2565 }
2566 }
2567 #endif //ASSERT
2568
2569 //------------------------------dump------------------------------------------
2570 // Dump a Node
2571 void Node::dump(const char* suffix, bool mark, outputStream* st, DumpConfig* dc) const {
2572 Compile* C = Compile::current();
2573 bool is_new = C->node_arena()->contains(this);
2574 C->_in_dump_cnt++;
2575
2576 // idx mark name ===
2577 dump_idx(true, st, dc);
2578 st->print(mark ? " >" : " ");
2579 dump_name(st, dc);
2580 st->print(" === ");
2581
2582 // Dump the required and precedence inputs
2583 dump_req(st, dc);
2584 dump_prec(st, dc);
2585 // Dump the outputs
2586 dump_out(st, dc);
2587
2588 if (is_disconnected(this)) {
2589 #ifdef ASSERT
2590 st->print(" [" UINT64_FORMAT "]", debug_idx());
2591 dump_orig(st);
2592 #endif
2593 st->cr();
2594 C->_in_dump_cnt--;
2595 return; // don't process dead nodes
2596 }
2597
2598 if (C->clone_map().value(_idx) != 0) {
2599 C->clone_map().dump(_idx, st);
2600 }
2601 // Dump node-specific info
2602 dump_spec(st);
2603 #ifdef ASSERT
2604 // Dump the non-reset _debug_idx
2605 if (Verbose && WizardMode) {
2606 st->print(" [" UINT64_FORMAT "]", debug_idx());
2607 }
2608 #endif
2609
2610 const Type *t = bottom_type();
2611
2612 if (t != nullptr && (t->isa_instptr() || t->isa_instklassptr())) {
2613 const TypeInstPtr *toop = t->isa_instptr();
2614 const TypeInstKlassPtr *tkls = t->isa_instklassptr();
2615 if (toop) {
2616 st->print(" Oop:");
2617 } else if (tkls) {
2618 st->print(" Klass:");
2619 }
2620 t->dump_on(st);
2621 } else if (t == Type::MEMORY) {
2622 st->print(" Memory:");
2623 MemNode::dump_adr_type(adr_type(), st);
2624 } else if (Verbose || WizardMode) {
2625 st->print(" Type:");
2626 if (t) {
2627 t->dump_on(st);
2628 } else {
2629 st->print("no type");
2630 }
2631 } else if (t->isa_vect() && this->is_MachSpillCopy()) {
2632 // Dump MachSpillcopy vector type.
2633 t->dump_on(st);
2634 }
2635 if (is_new) {
2636 DEBUG_ONLY(dump_orig(st));
2637 Node_Notes* nn = C->node_notes_at(_idx);
2638 if (nn != nullptr && !nn->is_clear()) {
2639 if (nn->jvms() != nullptr) {
2640 st->print(" !jvms:");
2641 nn->jvms()->dump_spec(st);
2642 }
2643 }
2644 }
2645 if (suffix) st->print("%s", suffix);
2646 C->_in_dump_cnt--;
2647 }
2648
2649 // call from debugger: dump node to tty with newline
2650 void Node::dump() const {
2651 dump("\n");
2652 }
2653
2654 //------------------------------dump_req--------------------------------------
2655 void Node::dump_req(outputStream* st, DumpConfig* dc) const {
2656 // Dump the required input edges
2657 for (uint i = 0; i < req(); i++) { // For all required inputs
2658 Node* d = in(i);
2659 if (d == nullptr) {
2660 st->print("_ ");
2661 } else if (not_a_node(d)) {
2662 st->print("not_a_node "); // uninitialized, sentinel, garbage, etc.
2663 } else {
2664 d->dump_idx(false, st, dc);
2665 st->print(" ");
2666 }
2667 }
2668 }
2669
2670
2671 //------------------------------dump_prec-------------------------------------
2672 void Node::dump_prec(outputStream* st, DumpConfig* dc) const {
2673 // Dump the precedence edges
2674 int any_prec = 0;
2675 for (uint i = req(); i < len(); i++) { // For all precedence inputs
2676 Node* p = in(i);
2677 if (p != nullptr) {
2678 if (!any_prec++) st->print(" |");
2679 if (not_a_node(p)) { st->print("not_a_node "); continue; }
2680 p->dump_idx(false, st, dc);
2681 st->print(" ");
2682 }
2683 }
2684 }
2685
2686 //------------------------------dump_out--------------------------------------
2687 void Node::dump_out(outputStream* st, DumpConfig* dc) const {
2688 // Delimit the output edges
2689 st->print(" [[ ");
2690 // Dump the output edges
2691 for (uint i = 0; i < _outcnt; i++) { // For all outputs
2692 Node* u = _out[i];
2693 if (u == nullptr) {
2694 st->print("_ ");
2695 } else if (not_a_node(u)) {
2696 st->print("not_a_node ");
2697 } else {
2698 u->dump_idx(false, st, dc);
2699 st->print(" ");
2700 }
2701 }
2702 st->print("]] ");
2703 }
2704
2705 //------------------------------dump-------------------------------------------
2706 // call from debugger: dump Node's inputs (or outputs if d negative)
2707 void Node::dump(int d) const {
2708 dump_bfs(abs(d), nullptr, (d > 0) ? "+$" : "-$");
2709 }
2710
2711 //------------------------------dump_ctrl--------------------------------------
2712 // call from debugger: dump Node's control inputs (or outputs if d negative)
2713 void Node::dump_ctrl(int d) const {
2714 dump_bfs(abs(d), nullptr, (d > 0) ? "+$c" : "-$c");
2715 }
2716
2717 //-----------------------------dump_compact------------------------------------
2718 void Node::dump_comp() const {
2719 this->dump_comp("\n");
2720 }
2721
2722 //-----------------------------dump_compact------------------------------------
2723 // Dump a Node in compact representation, i.e., just print its name and index.
2724 // Nodes can specify additional specifics to print in compact representation by
2725 // implementing dump_compact_spec.
2726 void Node::dump_comp(const char* suffix, outputStream *st) const {
2727 Compile* C = Compile::current();
2728 C->_in_dump_cnt++;
2729 st->print("%s(%d)", Name(), _idx);
2730 this->dump_compact_spec(st);
2731 if (suffix) {
2732 st->print("%s", suffix);
2733 }
2734 C->_in_dump_cnt--;
2735 }
2736
2737 // VERIFICATION CODE
2738 // Verify all nodes if verify_depth is negative
2739 void Node::verify(int verify_depth, VectorSet& visited, Node_List& worklist) {
2740 assert(verify_depth != 0, "depth should not be 0");
2741 Compile* C = Compile::current();
2742 uint last_index_on_current_depth = worklist.size() - 1;
2743 verify_depth--; // Visiting the first node on depth 1
2744 // Only add nodes to worklist if verify_depth is negative (visit all nodes) or greater than 0
2745 bool add_to_worklist = verify_depth != 0;
2746
2747 for (uint list_index = 0; list_index < worklist.size(); list_index++) {
2748 Node* n = worklist[list_index];
2749
2750 if (n->is_Con() && n->bottom_type() == Type::TOP) {
2751 if (C->cached_top_node() == nullptr) {
2752 C->set_cached_top_node((Node*)n);
2753 }
2754 assert(C->cached_top_node() == n, "TOP node must be unique");
2755 }
2756
2757 uint in_len = n->len();
2758 for (uint i = 0; i < in_len; i++) {
2759 Node* x = n->_in[i];
2760 if (!x || x->is_top()) {
2761 continue;
2762 }
2763
2764 // Verify my input has a def-use edge to me
2765 // Count use-def edges from n to x
2766 int cnt = 1;
2767 for (uint j = 0; j < i; j++) {
2768 if (n->_in[j] == x) {
2769 cnt++;
2770 break;
2771 }
2772 }
2773 if (cnt == 2) {
2774 // x is already checked as n's previous input, skip its duplicated def-use count checking
2775 continue;
2776 }
2777 for (uint j = i + 1; j < in_len; j++) {
2778 if (n->_in[j] == x) {
2779 cnt++;
2780 }
2781 }
2782
2783 // Count def-use edges from x to n
2784 uint max = x->_outcnt;
2785 for (uint k = 0; k < max; k++) {
2786 if (x->_out[k] == n) {
2787 cnt--;
2788 }
2789 }
2790 assert(cnt == 0, "mismatched def-use edge counts");
2791
2792 if (add_to_worklist && !visited.test_set(x->_idx)) {
2793 worklist.push(x);
2794 }
2795 }
2796
2797 if (verify_depth > 0 && list_index == last_index_on_current_depth) {
2798 // All nodes on this depth were processed and its inputs are on the worklist. Decrement verify_depth and
2799 // store the current last list index which is the last node in the list with the new depth. All nodes
2800 // added afterwards will have a new depth again. Stop adding new nodes if depth limit is reached (=0).
2801 verify_depth--;
2802 if (verify_depth == 0) {
2803 add_to_worklist = false;
2804 }
2805 last_index_on_current_depth = worklist.size() - 1;
2806 }
2807 }
2808 }
2809 #endif // not PRODUCT
2810
2811 //------------------------------Registers--------------------------------------
2812 // Do we Match on this edge index or not? Generally false for Control
2813 // and true for everything else. Weird for calls & returns.
2814 uint Node::match_edge(uint idx) const {
2815 return idx; // True for other than index 0 (control)
2816 }
2817
2818 // Register classes are defined for specific machines
2819 const RegMask &Node::out_RegMask() const {
2820 ShouldNotCallThis();
2821 return RegMask::EMPTY;
2822 }
2823
2824 const RegMask &Node::in_RegMask(uint) const {
2825 ShouldNotCallThis();
2826 return RegMask::EMPTY;
2827 }
2828
2829 void Node_Array::grow(uint i) {
2830 assert(i >= _max, "Should have been checked before, use maybe_grow?");
2831 assert(_max > 0, "invariant");
2832 uint old = _max;
2833 _max = next_power_of_2(i);
2834 _nodes = (Node**)_a->Arealloc( _nodes, old*sizeof(Node*),_max*sizeof(Node*));
2835 Copy::zero_to_bytes( &_nodes[old], (_max-old)*sizeof(Node*) );
2836 }
2837
2838 void Node_Array::insert(uint i, Node* n) {
2839 if (_nodes[_max - 1]) {
2840 grow(_max);
2841 }
2842 Copy::conjoint_words_to_higher((HeapWord*)&_nodes[i], (HeapWord*)&_nodes[i + 1], ((_max - i - 1) * sizeof(Node*)));
2843 _nodes[i] = n;
2844 }
2845
2846 void Node_Array::remove(uint i) {
2847 Copy::conjoint_words_to_lower((HeapWord*)&_nodes[i + 1], (HeapWord*)&_nodes[i], ((_max - i - 1) * sizeof(Node*)));
2848 _nodes[_max - 1] = nullptr;
2849 }
2850
2851 void Node_Array::dump() const {
2852 #ifndef PRODUCT
2853 for (uint i = 0; i < _max; i++) {
2854 Node* nn = _nodes[i];
2855 if (nn != nullptr) {
2856 tty->print("%5d--> ",i); nn->dump();
2857 }
2858 }
2859 #endif
2860 }
2861
2862 //--------------------------is_iteratively_computed------------------------------
2863 // Operation appears to be iteratively computed (such as an induction variable)
2864 // It is possible for this operation to return false for a loop-varying
2865 // value, if it appears (by local graph inspection) to be computed by a simple conditional.
2866 bool Node::is_iteratively_computed() {
2867 if (ideal_reg()) { // does operation have a result register?
2868 for (uint i = 1; i < req(); i++) {
2869 Node* n = in(i);
2870 if (n != nullptr && n->is_Phi()) {
2871 for (uint j = 1; j < n->req(); j++) {
2872 if (n->in(j) == this) {
2873 return true;
2874 }
2875 }
2876 }
2877 }
2878 }
2879 return false;
2880 }
2881
2882 //--------------------------find_similar------------------------------
2883 // Return a node with opcode "opc" and same inputs as "this" if one can
2884 // be found; Otherwise return null;
2885 Node* Node::find_similar(int opc) {
2886 if (req() >= 2) {
2887 Node* def = in(1);
2888 if (def && def->outcnt() >= 2) {
2889 for (DUIterator_Fast dmax, i = def->fast_outs(dmax); i < dmax; i++) {
2890 Node* use = def->fast_out(i);
2891 if (use != this &&
2892 use->Opcode() == opc &&
2893 use->req() == req() &&
2894 has_same_inputs_as(use)) {
2895 return use;
2896 }
2897 }
2898 }
2899 }
2900 return nullptr;
2901 }
2902
2903 bool Node::has_same_inputs_as(const Node* other) const {
2904 assert(req() == other->req(), "should have same number of inputs");
2905 for (uint j = 0; j < other->req(); j++) {
2906 if (in(j) != other->in(j)) {
2907 return false;
2908 }
2909 }
2910 return true;
2911 }
2912
2913 Node* Node::unique_multiple_edges_out_or_null() const {
2914 Node* use = nullptr;
2915 for (DUIterator_Fast kmax, k = fast_outs(kmax); k < kmax; k++) {
2916 Node* u = fast_out(k);
2917 if (use == nullptr) {
2918 use = u; // first use
2919 } else if (u != use) {
2920 return nullptr; // not unique
2921 } else {
2922 // secondary use
2923 }
2924 }
2925 return use;
2926 }
2927
2928 //--------------------------unique_ctrl_out_or_null-------------------------
2929 // Return the unique control out if only one. Null if none or more than one.
2930 Node* Node::unique_ctrl_out_or_null() const {
2931 Node* found = nullptr;
2932 for (uint i = 0; i < outcnt(); i++) {
2933 Node* use = raw_out(i);
2934 if (use->is_CFG() && use != this) {
2935 if (found != nullptr) {
2936 return nullptr;
2937 }
2938 found = use;
2939 }
2940 }
2941 return found;
2942 }
2943
2944 //--------------------------unique_ctrl_out------------------------------
2945 // Return the unique control out. Asserts if none or more than one control out.
2946 Node* Node::unique_ctrl_out() const {
2947 Node* ctrl = unique_ctrl_out_or_null();
2948 assert(ctrl != nullptr, "control out is assumed to be unique");
2949 return ctrl;
2950 }
2951
2952 void Node::ensure_control_or_add_prec(Node* c) {
2953 if (in(0) == nullptr) {
2954 set_req(0, c);
2955 } else if (in(0) != c) {
2956 add_prec(c);
2957 }
2958 }
2959
2960 void Node::add_prec_from(Node* n) {
2961 for (uint i = n->req(); i < n->len(); i++) {
2962 Node* prec = n->in(i);
2963 if (prec != nullptr) {
2964 add_prec(prec);
2965 }
2966 }
2967 }
2968
2969 bool Node::is_dead_loop_safe() const {
2970 if (is_Phi()) {
2971 return true;
2972 }
2973 if (is_Proj() && in(0) == nullptr) {
2974 return true;
2975 }
2976 if ((_flags & (Flag_is_dead_loop_safe | Flag_is_Con)) != 0) {
2977 if (!is_Proj()) {
2978 return true;
2979 }
2980 if (in(0)->is_Allocate()) {
2981 return false;
2982 }
2983 // MemNode::can_see_stored_value() peeks through the boxing call
2984 if (in(0)->is_CallStaticJava() && in(0)->as_CallStaticJava()->is_boxing_method()) {
2985 return false;
2986 }
2987 return true;
2988 }
2989 return false;
2990 }
2991
2992 bool Node::is_div_or_mod(BasicType bt) const { return Opcode() == Op_Div(bt) || Opcode() == Op_Mod(bt) ||
2993 Opcode() == Op_UDiv(bt) || Opcode() == Op_UMod(bt); }
2994
2995 // `maybe_pure_function` is assumed to be the input of `this`. This is a bit redundant,
2996 // but we already have and need maybe_pure_function in all the call sites, so
2997 // it makes it obvious that the `maybe_pure_function` is the same node as in the caller,
2998 // while it takes more thinking to realize that a locally computed in(0) must be equal to
2999 // the local in the caller.
3000 bool Node::is_data_proj_of_pure_function(const Node* maybe_pure_function) const {
3001 return Opcode() == Op_Proj && as_Proj()->_con == TypeFunc::Parms && maybe_pure_function->is_CallLeafPure();
3002 }
3003
3004 //--------------------------has_non_debug_uses------------------------------
3005 // Checks whether the node has any non-debug uses or not.
3006 bool Node::has_non_debug_uses() const {
3007 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
3008 Node* u = fast_out(i);
3009 if (u->is_SafePoint()) {
3010 if (u->is_Call() && u->as_Call()->has_non_debug_use(this)) {
3011 return true;
3012 }
3013 // Non-call safepoints have only debug uses.
3014 } else if (u->is_ReachabilityFence()) {
3015 // Reachability fence is treated as debug use.
3016 } else {
3017 return true; // everything else is conservatively treated as non-debug use
3018 }
3019 }
3020 return false; // no non-debug uses found
3021 }
3022
3023 //=============================================================================
3024 //------------------------------yank-------------------------------------------
3025 // Find and remove
3026 void Node_List::yank( Node *n ) {
3027 uint i;
3028 for (i = 0; i < _cnt; i++) {
3029 if (_nodes[i] == n) {
3030 break;
3031 }
3032 }
3033
3034 if (i < _cnt) {
3035 _nodes[i] = _nodes[--_cnt];
3036 }
3037 }
3038
3039 //------------------------------dump-------------------------------------------
3040 void Node_List::dump() const {
3041 #ifndef PRODUCT
3042 for (uint i = 0; i < _cnt; i++) {
3043 if (_nodes[i]) {
3044 tty->print("%5d--> ", i);
3045 _nodes[i]->dump();
3046 }
3047 }
3048 #endif
3049 }
3050
3051 void Node_List::dump_simple() const {
3052 #ifndef PRODUCT
3053 for (uint i = 0; i < _cnt; i++) {
3054 if( _nodes[i] ) {
3055 tty->print(" %d", _nodes[i]->_idx);
3056 } else {
3057 tty->print(" null");
3058 }
3059 }
3060 #endif
3061 }
3062
3063 //=============================================================================
3064 //------------------------------remove-----------------------------------------
3065 void Unique_Node_List::remove(Node* n) {
3066 if (_in_worklist.test(n->_idx)) {
3067 for (uint i = 0; i < size(); i++) {
3068 if (_nodes[i] == n) {
3069 map(i, Node_List::pop());
3070 _in_worklist.remove(n->_idx);
3071 return;
3072 }
3073 }
3074 ShouldNotReachHere();
3075 }
3076 }
3077
3078 //-----------------------remove_useless_nodes----------------------------------
3079 // Remove useless nodes from worklist
3080 void Unique_Node_List::remove_useless_nodes(VectorSet &useful) {
3081 for (uint i = 0; i < size(); ++i) {
3082 Node *n = at(i);
3083 assert( n != nullptr, "Did not expect null entries in worklist");
3084 if (!useful.test(n->_idx)) {
3085 _in_worklist.remove(n->_idx);
3086 map(i, Node_List::pop());
3087 --i; // Visit popped node
3088 // If it was last entry, loop terminates since size() was also reduced
3089 }
3090 }
3091 }
3092
3093 //=============================================================================
3094 void Node_Stack::grow() {
3095 size_t old_top = pointer_delta(_inode_top,_inodes,sizeof(INode)); // save _top
3096 size_t old_max = pointer_delta(_inode_max,_inodes,sizeof(INode));
3097 size_t max = old_max << 1; // max * 2
3098 _inodes = REALLOC_ARENA_ARRAY(_a, _inodes, old_max, max);
3099 _inode_max = _inodes + max;
3100 _inode_top = _inodes + old_top; // restore _top
3101 }
3102
3103 // Node_Stack is used to map nodes.
3104 Node* Node_Stack::find(uint idx) const {
3105 uint sz = size();
3106 for (uint i = 0; i < sz; i++) {
3107 if (idx == index_at(i)) {
3108 return node_at(i);
3109 }
3110 }
3111 return nullptr;
3112 }
3113
3114 //=============================================================================
3115 uint TypeNode::size_of() const { return sizeof(*this); }
3116 #ifndef PRODUCT
3117 void TypeNode::dump_spec(outputStream *st) const {
3118 if (!Verbose && !WizardMode) {
3119 // standard dump does this in Verbose and WizardMode
3120 st->print(" #"); _type->dump_on(st);
3121 }
3122 }
3123
3124 void TypeNode::dump_compact_spec(outputStream *st) const {
3125 st->print("#");
3126 _type->dump_on(st);
3127 }
3128 #endif
3129 uint TypeNode::hash() const {
3130 return Node::hash() + _type->hash();
3131 }
3132 bool TypeNode::cmp(const Node& n) const {
3133 return Type::equals(_type, n.as_Type()->_type);
3134 }
3135 const Type* TypeNode::bottom_type() const { return _type; }
3136 const Type* TypeNode::Value(PhaseGVN* phase) const { return _type; }
3137
3138 //------------------------------ideal_reg--------------------------------------
3139 uint TypeNode::ideal_reg() const {
3140 return _type->ideal_reg();
3141 }
3142
3143 void TypeNode::make_path_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, Node* ctrl_use, uint j, const char* phase_str) {
3144 Node* c = ctrl_use->in(j);
3145 if (igvn->type(c) != Type::TOP) {
3146 igvn->replace_input_of(ctrl_use, j, igvn->C->top());
3147 create_halt_path(igvn, c, loop, phase_str);
3148 }
3149 }
3150
3151 // This Type node is dead. It could be because the type that it captures and the type of the node computed from its
3152 // inputs do not intersect anymore. That node has some uses along some control flow paths. Those control flow paths must
3153 // be unreachable as using a dead value makes no sense. For the Type node to capture a narrowed down type, some control
3154 // flow construct must guard the Type node (an If node usually). When the Type node becomes dead, the guard usually
3155 // constant folds and the control flow that leads to the Type node becomes unreachable. There are cases where that
3156 // doesn't happen, however. They are handled here by following uses of the Type node until a CFG or a Phi to find dead
3157 // paths. The dead paths are then replaced by a Halt node.
3158 void TypeNode::make_paths_from_here_dead(PhaseIterGVN* igvn, PhaseIdealLoop* loop, const char* phase_str) {
3159 Unique_Node_List wq;
3160 wq.push(this);
3161 for (uint i = 0; i < wq.size(); ++i) {
3162 Node* n = wq.at(i);
3163 for (DUIterator_Fast kmax, k = n->fast_outs(kmax); k < kmax; k++) {
3164 Node* u = n->fast_out(k);
3165 if (u->is_CFG()) {
3166 assert(!u->is_Region(), "Can't reach a Region without going through a Phi");
3167 make_path_dead(igvn, loop, u, 0, phase_str);
3168 } else if (u->is_Phi()) {
3169 Node* r = u->in(0);
3170 assert(r->is_Region() || r->is_top(), "unexpected Phi's control");
3171 if (r->is_Region()) {
3172 for (uint j = 1; j < u->req(); ++j) {
3173 if (u->in(j) == n && r->in(j) != nullptr) {
3174 make_path_dead(igvn, loop, r, j, phase_str);
3175 }
3176 }
3177 }
3178 } else {
3179 wq.push(u);
3180 }
3181 }
3182 }
3183 }
3184
3185 void TypeNode::create_halt_path(PhaseIterGVN* igvn, Node* c, PhaseIdealLoop* loop, const char* phase_str) const {
3186 Node* frame = new ParmNode(igvn->C->start(), TypeFunc::FramePtr);
3187 if (loop == nullptr) {
3188 igvn->register_new_node_with_optimizer(frame);
3189 } else {
3190 loop->register_new_node(frame, igvn->C->start());
3191 }
3192
3193 stringStream ss;
3194 ss.print("dead path discovered by TypeNode during %s", phase_str);
3195
3196 Node* halt = new HaltNode(c, frame, ss.as_string(igvn->C->comp_arena()));
3197 if (loop == nullptr) {
3198 igvn->register_new_node_with_optimizer(halt);
3199 } else {
3200 loop->register_control(halt, loop->ltree_root(), c);
3201 }
3202 igvn->add_input_to(igvn->C->root(), halt);
3203 }
3204
3205 Node* TypeNode::Ideal(PhaseGVN* phase, bool can_reshape) {
3206 if (KillPathsReachableByDeadTypeNode && can_reshape && Value(phase) == Type::TOP) {
3207 PhaseIterGVN* igvn = phase->is_IterGVN();
3208 Node* top = igvn->C->top();
3209 ResourceMark rm;
3210 make_paths_from_here_dead(igvn, nullptr, "igvn");
3211 return top;
3212 }
3213
3214 return Node::Ideal(phase, can_reshape);
3215 }
--- EOF ---